If Western countries supply Ukraine with F-16 fighters, the aircraft will not alter the situation on the battlefield, Russian news agencies quoted President Vladimir Putin as telling military pilots on Wednesday.
But the fighters, he was quoted as saying, can carry nuclear weapons and Moscow would have to take account of that in its military planning.
"If they supply F-16s, and they are talking about this and are apparently training pilots, this will not change the situation on the battlefield," Tass quoted Putin as telling pilots at a gathering northwest of Moscow.
"And we will destroy the aircraft just as we destroy today tanks, armoured vehicles and other equipment, including multiple rocket launchers."
Putin noted that the fighters had the capability to carry nuclear weapons "and we also must consider that in the way we organise matters".
The F-16s, he said, would be legitimate targets, wherever they might be.
"Of course, if they will be used from airfields in third countries, they become for us legitimate targets, wherever they might be located," he was quoted as saying.
Putin's remarks followed comments earlier in the day by Ukrainian Foreign Minister Dmytro Kuleba that the aircraft should arrive in Ukraine in the coming months.
Ukraine, now more than two years into a full-fledged war against Russia, has sought F-16s for many months.
Belgium, Denmark, Norway and the Netherlands are among countries which have pledged to donate F-16s. A coalition of countries has promised to help train Ukrainian pilots in their use.
