Russian President Vladimir Putin on Friday said that a clash of North Atlantic Treaty Organization, or NATO, troops with his forces would lead to a global catastrophe, reported Reuters.

“I hope that those who are saying this are smart enough not to take such steps,” Putin said at a news conference in the Kazakhstan capital of Astana.

Putin also said that there was no need for massive new strikes on Ukraine as most designated targets have been hit and that Russia was not looking to destroy the country. He said that his call-up of Russian reservists would be over within two weeks but there were no plans for mobilising the troops.

The president added that Russia is willing to hold talks but it would require international mediation if Ukraine wanted to take part.

Russia had launched an invasion of Ukraine on February 24. The Kremlin described its actions as a “special operation” to demilitarise and “de-Nazify” Ukraine. However, Kyiv and several Western nations have said that this is a baseless pretext for a war of choice by Russian President Vladimir Putin.

Putin said he had no regrets about attacking Ukraine, saying failing to act against the country would have been worse.

“I want it to be clear: what is happening today is unpleasant, to put it mildly, but we would have got the same thing a little later, only in worse conditions for us, that’s all,” he added. “So we are acting correctly and in a timely manner.”