President Trump has pulled out of a historic summit in Singapore with North Korean Leader Kim Jong Un, which had been scheduled for June 12, calling it "a truly sad moment in history."

In an open letter, Trump told Kim "we greatly appreciate your time, patience, and effort with respect to our recent negotiations" and that "I was very much looking forward to being there with you," but that "it is inappropriate, at this time, to have this long-planned meeting" due to increasing tensions between the parties. A North Korean vice minister of foreign affairs called Vice President Mike Pence "ignorant" and "stupid" on Thursday for comparing North Korea to Libya, and warned Kim would cancel the summit if the U.S. didn't stop its threats.

Read the letter in full below. Jeva Lange

Attorney General William Barr is pushing back against criticism that he is using his position to protect President Trump.

During an interview with The Wall Street Journal on Monday, Barr said that before becoming Trump's attorney general, he saw the president was the focus of several investigations, and felt "the rules were being changed to hurt Trump, and I thought it was damaging for the presidency over the long haul."

Barr wrote a 19-page memo to the Department of Justice last year, saying Special Counsel Robert Mueller's obstruction inquiry hurt the presidency; after the report was released, Barr decided that several incidents of potential obstruction described in Mueller's report were not criminal. "At every grave juncture the presidency has done what it is supposed to do, which is to provide leadership and direction," Barr said. "If you destroy the presidency and make it an errand boy for Congress, we're going to be a much weaker and more divided nation."

Barr's critics have called him out for refusing to turn over an unredacted copy of Mueller's report to the House Judiciary Committee, which led to the panel voting to hold him in contempt; ordering a review into the origins of the Russia investigation; and telling lawmakers that Trump campaign associates were the victims of "spying." All of this is "an affront to everyone who worked on that case and who supported it, and to everyone who works counterintelligence in general," former top FBI counterintelligence agent Frank Montoya told the Journal. Catherine Garcia

During a closed-door hearing earlier this year, President Trump's former personal attorney Michael Cohen told the House Intelligence Committee that Trump's lawyer Jay Sekulow instructed him to lie to Congress in 2017 regarding negotiations to build a Trump Tower in Moscow, people familiar with his testimony told The Washington Post on Monday.

Cohen launched the Moscow project in September 2015, and told Congress discussions ended in January 2016; he later admitted the negotiations continued into June 2016. Cohen said he lied to help obscure the fact that while Trump was running for president, he was involved in a project with potentially hundreds of millions of dollars at stake. He is now in prison for lying to Congress, campaign finance violations, and financial crimes.

During his private testimony, Cohen told lawmakers Sekulow encouraged him to say negotiations ended on Jan. 31, 2016, since the Iowa caucuses were on Feb. 1, the Post reports. Sekulow joined Trump's legal team following the election, and the Post notes it's not clear how much Sekulow actually knew about the Trump Tower Moscow project. Sekulow's attorneys told the Post relying on Cohen's word "defies logic, well-established law, and common sense." House Intelligence Committee Chair Adam Schiff (D-Calif.) said his panel is now investigating whether Sekulow or any of Trump's other attorneys "participated in the false testimony" Cohen gave to lawmakers. Catherine Garcia

President Trump's attempt to block a subpoena from House Democrats has been overruled.

Washington, D.C. District Court Judge Amit Mehta ruled Monday that Trump could not block the House Oversight Committee's subpoena of his financial records from his accounting firm. Mehta also denied Trump's lawyers' request to stay the ruling, meaning the firm is now supposed to hand over eight years' worth of Trump's records, Politico reports.

House Oversight Chair Elijah Cummings (D-Md.) subpoenaed Trump's accounting firm last month as part of Democrats' ongoing attempts to access the president's tax returns. He asked for the records first, but officially subpoenaed them after Trump's former lawyer Michael Cohen testified that the president had inflated his wealth on past financial statements. Trump quickly sued Cummings in return.

Trump's lawyers' argument revolved around claiming Congress' records requests were made for "a law-enforcement purpose" rather than "to work on legislation." Yet in the process, those lawyers implied the Whitewater and Watergate investigations were invalid, leaving Mehta visibily skeptical.

In his Monday ruling, Mehta said "it is not for the court to question whether the committee's actions are truly motivated by political considerations" and ruled in the committee's favor. Trump's lawyers are expected to appeal the decision immediately, setting it up for a decision in a circuit court.

In another subpoena-blocking move, Trump also sued a few banks to stop them from handing over his financial records as well. That suit is still ongoing in a Manhattan court. The Week Staff

President Trump doesn't want former White House Counsel Don McGahn in front of Congress.

The West Winger turned fascinating Mueller report witness was subpoenaed by the House Judiciary Committee for testimony last week, though Trump has publicly said he wouldn't let McGahn attend. McGahn isn't in the administration anymore, but that didn't stop the Department of Justice from issuing a 15-page letter spelling out why McGahn could not legally be called to testify, and it didn't stop Trump from publicly directing him not to testify on Monday.

In the Monday letter to current White House Counsel Pat Cipollone, Assistant Attorney General Steven Engel wrote that "Congress cannot constitutionally compel the president's senior advisers to testify about their official duties." He specifically cited an opinion from former President Bill Clinton's Attorney General Janet Reno, along with precedents from throughout presidential administrations. White House Press Secretary summed up this "bipartisan and constitutional precedent" in a statement, and affirmed that Trump had directed McGahn not to testify.

McGahn still hasn't said if he'll comply with Trump's order, but he faces a pitfall either way. If McGahn ignores Trump and testifies, he'll likely "damage his own career in Republican politics, but also put his law firm" at risk because Trump could tell its GOP clients to "withhold their business," The New York Times explains. But if McGahn steps out on Congress, he could face a contempt charge. Judging by Attorney General William Barr's jokes in the past few days, though, that doesn't seem to matter much. The Week Staff

A group of scientists from Stanford University have proposed a rather unconventional plan to fight climate change.

Their research, published on Monday in Nature Sustainability, concluded that converting methane into carbon dioxide could actually help reduce the warming of the Earth. Methane and carbon dioxide are both so-called "greenhouse gases" — in fact, carbon dioxide is largely responsible for the climate predicament we find ourselves in, the Los Angeles Times explained. But as it turns out, more carbon dioxide might not be as disastrous as we think.

Methane traps much more heat than carbon dioxide, "on a molecule-for-molecule basis." So by converting much of our atmospheric methane into carbon dioxide, we could dramatically reduce the impact of climate change. This process would eliminate about one-sixth of human-caused global warming, while only adding a few months' worth of carbon dioxide to the atmosphere, researchers found.

Of course, the best case scenario would be to stop greenhouse gas emissions entirely, as many scientists have been saying for years. But since that hasn't been a very popular plan, this could be the next best thing. Converting methane into carbon dioxide "would not be a deal-breaker," said Rob Jackson, the study's lead author.

Further research will be required in order to determine whether this plan would be realistic to achieve, but the study's authors are "cautiously optimistic." Learn more at the Los Angeles Times. Shivani Ishwar

Game of Thrones just went out on top by breaking another viewership record.

The series' final episode, "The Iron Throne," drew 19.3 million viewers on Sunday, The Hollywood Reporter writes. This includes 13.6 million people who tuned into the initial 9:00 p.m. airing, as well as those who tuned in for replays and those who streamed the episode online.

This breaks Game of Thrones' previous ratings record — 18.4 million people tuned in last Sunday night to the season's fifth episode, "The Bells." It also sets a new record for HBO itself. The season 4 premiere of The Sopranos previously held the HBO record for biggest linear audience with 13.4 million viewers in 2002, although this was before the rise of streaming.

These impressive viewership numbers Game of Thrones has been drawing each week don't factor in those who watch the episode beyond Sunday night. When including those who watch later, HBO says the eighth season has been averaging 44.2 million viewers, Deadline reports.

Now, the network can only hope to retain these tens of millions of viewers for the forthcoming Game of Thrones spinoffs and that fans' watch hasn't ended quite yet. Brendan Morrow