Russian foreign minister Sergei Lavrov is warning, again, of an “escalation” in the war in Ukraine if western allies provide F-16 fighter jets for use in the conflict.

“We must keep in mind that one of the modifications of the F-16 can ‘accommodate’ nuclear weapons,” he said Tuesday in a speech at a military base in Dushanbe, Tajikistan, according to Reuters.

“If they do not understand this, then they are worthless as military strategists and planners.”

A number of nations, including the UK, have said in recent weeks that they want to help procure the fighter jets for Ukraine. Joe Biden has not committed to supplying aircraft, but has said the US will back an international effort to train Ukrainian pilots to fly them before doing so.

ohn Kirby, White House coordinator of strategic communications for the National Security Council, spoke to reporters about F-16s on Tuesday:

"The purpose of providing advanced fighter aircraft is to help Ukraine defend itself defend its airspace and its territorial integrity, period".

To Lavrov, he added:

"If you’re worried about Ukrainian military capabilities, then you should take your troops and leave Ukraine".