Biden landed in London on Sunday night to kick off a three-nation trip that will feature a NATO summit in Lithuania aimed at showing solidarity with Ukraine in its fight against Russia while not yet accepting Kyiv as a member of the defense alliance.
"The president has huge respect for the king's commitment on the climate issue in particular. He has been a clarion voice on this issue," White House national security adviser Jake Sullivan told reporters aboard Air Force One on Sunday. Biden will also travel to 10 Downing Street on Monday to hold a low-key meeting with Sunak, their fifth in as many months. Sullivan said the visit is more of a continuation of a long-running conversation than formal meeting. It will mark Biden's first visit to Downing Street as president.
Ahead of the trip, Biden urged caution for now on Ukraine's drive to join NATO, saying the alliance could get drawn into the war with Russia due to NATO's mutual defense pact.