American officials quickly discovered a major snag in planning for the summit: summertime is peak tourist season in Alaska, and options both available and equipped to host the two world leaders were severely limited.

The US president will speak to Ukraine's leader in a call on Wednesday, two days before "one-to-one" talks with Putin.

Friday's Alaska summit between U.S. President Donald Trump and Russian President Vladimir Putin "is a listening exercise for the president," the White House said on Tuesday, tempering expectations for a quick Russia-Ukraine ceasefire deal.