There are no constraints now on the U.S. and Russian nuclear weapons programmes, according to a non-proliferation expert.
Moscow claimed Ukraine attempted to attack Mr Putin’s Valdai residence in western Russia with 91 drones, all of which it said were shot down.
Authorities are investigating whether violations of aviation safety or operational rules contributed to the crash.
Poland has requested consultations under Article 4 of the NATO treaty relating to external threats, Prime Minister Donald Tusk said in Warsaw on Wednesday.
French President Emmanuel Macron has condemned the incursion of more than a dozen Russian drones into Polish airspace, calling it “simply unacceptable”.
“Last night in Poland, we saw the most serious European airspace violation by Russia since the war began, and indications suggest it was intentional, not accidental,” Ms Kallas stated.
The settlements are located on the outskirts of the regional capital, Kherson, on the northern bank of the Dnipro River.
Messrs Putin and Zelensky have not met since December 2019.
Switzerland points out that as the host of international conferences, it must grant exemptions for entry on such occasions.
The helicopter had five people on board.
