If Russian President Vladimir Putin threatens to use nuclear weapons against Ukraine, it will be a catastrophe for the world, but it will not break Ukraine, Ukrainian Foreign Minister Dmytro Kuleba has said.

"If President Putin's order to put his nuclear weapons on high alert is a direct threat to use these nuclear weapons against Ukraine, then I have a very simple message: it will be a disaster for the world, but it will not break us," Kuleba said at the online briefing on Sunday.

Kuleba said that Ukraine views this order by President Putin as an attempt to raise the stakes and put additional pressure on the Ukrainian negotiating delegation.

"This order of President Putin came immediately after there was an announcement that the two delegations were ready to meet. We see this order as an attempt to raise the stakes and put additional pressure on the Ukrainian delegation, but we will not succumb to this pressure," he said.

Kuleba added that Ukraine is ready to discuss in negotiations how to stop the war and de-occupy its territories.