President Trump said he'll know in the "first two minutes" whether his meeting on Friday with Vladimir Putin will be a success: REPORTER: Follow up on what you were saying there. First of all, Volodymyr Zelensky is not invited on Friday?

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.”

Ukrainian President Volodymyr Zelenskiy won diplomatic backing from Europe and the NATO alliance on Sunday ahead of a Russia-U.S. summit this week where Kyiv fears President Vladimir Putin and President Donald Trump may try to dictate terms for ending the 3-1/2-year war.