A direct confrontation between American and Russian forces in the Ukraine conflict must be avoided as it could lead to a third world war, US President Joe Biden has warned.
"I want to be clear: We will defend every inch of NATO territory with the full might of a united and galvanized NATO," Biden tweeted on Friday.
"But we will not fight a war against Russia in Ukraine," he added.
"A direct confrontation between NATO and Russia is World War III. And something we must strive to prevent," the US president explained.
At a Democratic Party event in Pennsylvania , Biden also commented on the debate about the proposed handover of fighter jets to Ukraine.
"The idea that we're going to send in offensive equipment and have planes and tanks and trains going in with American pilots and American crews (...) Don't kid yourself, no matter what y'all say. That's called World War III," Biden said.