Former Vice President Joe Biden says he is concerned about an apparent "romance" between the Trump administration and Russian President Vladimir Putin.
While declining to comment on an FBI probe of possible links between Russia and associates of President Donald Trump, Biden said "the whole notion that there's still this romance with Putin" was worrisome.
Biden cited Secretary of State Rex Tillerson's decision to skip an upcoming meeting of NATO foreign ministers in Belgium and visit Moscow as a cause for concern.
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The former vice president also said Trump's frequent comments on Twitter are "not helpful" and said Trump needs to understand that "the president's words matter a great deal" and have global repercussions.
"I hope the president will realise the campaign has to end and he's got to start to govern," Biden said.
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He and former President Barack Obama have tried to give Trump "an opportunity to get his sea legs" as president - without interference from them, Biden said, but "it's getting down to the wire for whether (Trump) is really going to take charge" as president.
Biden said he didn't know if Trump's comments about foreign policy showed "a lack of understanding of government and how international relations work" or were a reflection of "a policy prescription that's changing."
Either way, the American people should be concerned, he said, adding that the United States, "the most powerful, most respected nation in the world is sounding a very uncertain trumpet."
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