President-elect Donald Trump doesn't seem to have the support of his defense secretary nominee when it comes to scrapping the Iran nuclear deal on day one of his presidency. Retired Marine Gen. James Mattis said at his Senate confirmation hearing Thursday that while the deal is "an imperfect arms control agreement," he thinks the U.S. must uphold the deal — which Trump has dubbed "one of the dumbest deals ever."

Mattis argued the agreement, which involves the U.S. and five other countries lifting its sanctions on Iran in exchange for restrictions on its nuclear program, is integral to security in the region. "When America gives her word, we have to live up to it and work with our allies," Mattis said.

Watch Mattis diverge from Trump below. Becca Stanek

Whakaari/White Island, New Zealand's most active cone volcano, erupted on Monday, injuring as many as 20 people, authorities said.

The volcano is in the Bay of Plenty, and the island is a popular tourist attraction. Prime Minister Jacinda Ardern said it is believed that "100 people were on or around the island" when the volcano erupted, and some are unaccounted for. The government does not yet know if there have been any deaths.

Radio New Zealand said there are five helicopters, an ambulance crew, and a mobile triage unit on the way to the island, which is about 30 miles off the east coast of New Zealand's South Island. Catherine Garcia

House Judiciary Chairman Jerrold Nadler (D-N.Y.) believes the Democrats have a "solid" case for the impeachment of President Trump, he declared on CNN's State of the Union Sunday.

In fact, the case is so strong he's convinced if presented to a jury, it "would be a guilty verdict in about three minutes flat," Nadler said. There is "considerable direct evidence," he continued, and it "ill behooves the president or his partisans to say you don't have enough direct evidence when the reason we don't have even more direct evidence is the president has ordered everybody in the executive branch not to cooperate with Congress in the impeachment inquiry, something that is unprecedented in American history and is a contempt of Congress by itself."

On Monday, the Judiciary Committee will hold a hearing where evidence gathered by the Intelligence Committee will be presented. Nadler said the scope and nature of the articles of impeachment are still being considered, and won't be decided until after the hearing. "We'll bring articles of impeachment, presumably, before the committee at some point later in the week," he said on NBC's Meet the Press. The articles of impeachment are expected to center on abuse of presidential power in regards to Ukraine policy and obstruction of the impeachment probe. Catherine Garcia

The Saudi gunman who killed three people on Friday at Naval Air Station Pensacola in Florida went on Twitter before the shooting and accused the United States of being anti-Muslim, a U.S. official told The Associated Press on Sunday.

Saudi Royal Air Force 2nd Lt. Mohammad Saeed Alshamrani also apparently tweeted his anger over U.S. support of Israel. The FBI confirmed it is operating on the assumption the shooting was an act of terrorism, with investigators working to determine whether Alshamrani, 21, acted alone or with others. Alshamrani was in the U.S. for flight training, and was killed by a sheriff’s deputy during the attack.

The official also told AP that investigators believe Alshamrani went to New York City a few days before the shooting, and they are trying to figure out the purpose of his trip. A second U.S. official told AP on Saturday that Alshamrani hosted a dinner party prior to the attack during which he and three others watched videos of mass shootings.

Rachel J. Rojas, the special agent in charge of the FBI’s office in Jacksonville, said a Glock 9 mm weapon that had been legally purchased in Florida was used to carry out the shooting. In response, Florida Gov. Ron DeSantis (R) said he is against a "federal loophole" that lets foreigners purchase guns in the United States, and while he supports the Second Amendment, it "does not apply to Saudi Arabians." Catherine Garcia

Caroll Spinney, the actor and puppeteer who made Big Bird and Oscar the Grouch come alive on Sesame Street, died Sunday. He was 85.

The Sesame Workshop said Spinney, who died at his home in Connecticut, lived with dystonia for many years. Spinney began working on Sesame Street in its earliest days in 1969, before retiring in 2018.

As Big Bird, Spinney traveled around the world, conducted symphony orchestras, danced with the Rockettes, received a star on the Hollywood Walk of Fame, and was named a Living Legend by the Library of Congress.

In a statement, Sesame Workshop said Spinney's "enormous talent and outsized heart were perfectly suited to playing the larger-than-life yellow bird who brought joy to generations of children and countless fans of all ages around the world, and his loveably cantankerous grouch gave us all permission to be cranky once in a while." Catherine Garcia

The shooting — which is now being considered an act of terrorism — that resulted in three deaths at Naval Air Station Pensacola in Pensacola, Florida, on Friday has placed the United States' relationship with Saudi Arabia under a microscope.

The suspected shooter, identified as Saudi Royal Air Force 2nd Lt. Mohammad Saeed Alshamrani, was an aviation student at the base. The killing has led some people to question whether the partnership should continue, especially considering there have long been doubts about the alliance for a variety of reasons, most notably accusations of human rights abuses in Yemen and the murder of Saudi journalist Jamal Khashoggi.

But President Trump seems committed to U.S. policy toward Saudi Arabia, especially as his administration remains wary of Iran's influence in the Middle East. Trump said he spoke with Saudi Crown Prince Mohammad bin Salman after the shooting, who offered his condolences to family and friends of the deceased. There didn't, however, seem to be much in the way of rethinking the alliance.

That doesn't mean others haven't. Sen. Cory Booker (D-N.J.), who is aiming to challenge Trump as the next Democratic nominee, called the U.S. partnership with Saudi Arabia "unacceptable."

Rep. Matt Gaetz (R-Fla.), a supporter of Trump, said he was assured by Saudi Ambassador to the U.S. Princess Reema bint Bandar Al Saud that Saudi Arabia would not interfere with the investigation into the matter, unless requested. But he still said that Friday's shooting "has to inform" the U.S.-Saudi relationship. Tim O'Donnell

NBC's Chuck Todd really isn't sure why Sen. Ted Cruz (R-Texas), of all people, isn't more skeptical of President Trump.

Cruz, in an appearance on Sunday's edition of Meet the Press, said he still believes Ukraine interfered in the 2016 presidential election, which has become a major talking point among Republicans defending Trump during the impeachment inquiry that was spurred, in part, by Trump asking the Ukrainian government to investigate the claim.

As he did last week, when Sen. John Kennedy (R-La.) expressed a similar opinion, Todd seemed like he couldn't quite grasp what he was hearing. He then asked Cruz why he's so trusting of Trump considering he dealt with the president's attempts to manipulate a narrative about someone firsthand during the Republican primary battles in 2015 and 2016, including Trump's threat to "spill the beans" about Cruz's wife. The senator wasn't thrilled Todd brought that up, but he didn't backtrack on his comments about Ukraine.

Todd, for his part, wasn't buying Cruz's argument that Ukraine officials criticizing Trump during the election amounted to interference. The NBC host said Cruz, in comparing Ukraine's role in the elections to Russia, was basically comparing a pickpocket to Bernie Madoff. Tim O'Donnell