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Vladimir Putin is feeling excluded. The Russian president is reportedly offended that all he has gotten from President Trump so far is a handful of phone calls, while Trump has hung out with other world leaders, including Chinese President Xi Jinping, U.K. Prime Minister Theresa May, and Canadian Prime Minister Justin Trudeau.

"[The Russian leaders] feel slighted," explained foreign policy analyst Vladimir Frolov to The New York Times. Foreign affairs expert Aleksei Pushkov said: "Trump rejected the idea of holding a separate meeting [with Putin] early due to fear of hysteria by his enemies in the U.S.A."

Leaders in Moscow had believed Trump's election would lead to friendlier relations between the Kremlin and the White House, although the Trump administration has done little to prove that to be true. As recently as this weekend, Trump's national security adviser, Lt. Gen. H.R. McMaster, publicly scolded Putin on Fox News, saying, "We need changes in words and the nature of the relationship, but what we really need to see is a change in behavior."

"The Russians are basically scratching their heads and asking, 'What are we going to get from this?'" Pushkov said.