Earlier Thursday, when pushing back on Kremlin claims that a Trump-Putin summit had been set, a White House official had said Putin would also have to meet with Zelenskyy for the meeting to take place -- something the Kremlin has not been willing to commit to so far.

The vice president said the White House was trying to determine “when these three leaders could sit down and discuss an end to this conflict.”

President Donald Trump is open to holding a trilateral summit in Alaska with Russian President Vladimir Putin and Ukrainian President Volodymyr Zelenskiy, a White House official said on Saturday.