Dhaka, Aug. 20 -- U.S. President Donald Trump told President Volodymyr Zelenskiy on Monday that the United States would help guarantee Ukraine's security in any deal to end Russia's war there, though the extent of any assistance was not immediately clear.

Trump made the pledge during an extraordinary summit at the White House, where he hosted Zelenskiy and a group of European allies following his meeting on Friday in Alaska with Russian President Vladimir Putin.

"When it comes to security, there's going to be a lot of help," Trump told reporters, adding that European countries would be involved. "They are a first line of defence because they're there, but we'll help them out."

Zelenskiy hailed the promise as "a major step forward," addin...