Russia issued a warning on Saturday to Nato powers that are considering firmer responses to alleged Russian incursions, as Ukraine said it for the first time received a US-made Patriot system from Israel to ramp up defences.

Several European countries say Russian fighter jets and drones have violated their airspace over recent weeks, in what Nato has seen as a test of its resolve as Moscow presses on with its invasion of Ukraine.

"Russia is being accused of almost planning to attack the North Atlantic alliance and the European Union countries," Russian Foreign Minister Sergei Lavrov said in an address to the UN General Assembly.

"Russia has never had and does not have any such intentions. However, any aggression against my country will be met with a decisive response," he said.

Speaking later to reporters, Lavrov said that if any country downs objects still within Russian airspace, "they will very much regret it."

Nato -- which considers an attack on one ally an attack on all -- has been considering whether to shoot down Russian planes, in what would be a dramatic raising of the stakes with Russia.

US President Donald Trump on Tuesday voiced support for downing Russian planes.

Trump had once boasted of his warm ties with Russian President Vladimir Putin and invited him last month for talks in Alaska, ending the veteran Russian leader's ostracisation by the West since the conflict with Ukraine began in 2022.

But Trump has subsequently voiced frustration with Putin and said that Ukraine should seize back all the territory Russia has taken or even cross the border -- abruptly reversing his months of pressure on Kyiv to give up land in talks with Russia.

Lavrov went out of his way still to praise Trump, who despite his public musings on Putin has yet to impose long-threatened new economic sanctions on Russia.

"In the approaches of the current US administration, we see a desire not only to contribute to ways to realistically resolve the Ukrainian crisis, but also a desire to develop pragmatic cooperation without adopting an ideological stance," Lavrov said. (AFP)