French President Emmanuel Macron opened the door on Monday to European nations sending troops to Ukraine, although he cautioned that there was no consensus at this stage as allies agreed to ramp up efforts to deliver more munitions to Kyiv.

Some 20 European leaders gathered in Paris on Monday to send Russian President Vladimir Putin a message of European resolve on Ukraine and counter the Kremlin's narrative that Russia is bound to win a war now in its third year.

"There is no consensus at this stage... to send troops on the ground," Macron told reporters. "Nothing should be excluded. We will do everything that we must so that Russia does not win."

Macron invited his European counterparts to the Elysee palace for a hastily arranged meeting to discuss how to ramp up ammunition supplies to Ukraine amid what his advisers say is an escalation in Russian aggression over the past few weeks.

After initial successes in pushing back the Russian army, Ukraine has suffered setbacks on eastern battlefields, with its generals complaining of shortages of arms and soldiers.

Slovak Prime Minister Robert Fico, who has opposed military aid to Ukraine, said that several Nato and EU members were considering sending soldiers to Ukraine on a bilateral basis.

"I can confirm there are countries that are prepared to send their own troops to Ukraine, there are countries that say never, among which Slovakia belongs, and there are countries that say this proposal needs to be considered," he said before boarding his plane home.

Dutch Prime Minister Mark Rutte, who is the frontrunner to become the next secretary general of Nato, told reporters the issue of sending troops was not the focus of Monday's talks.

Addressing the leaders via videolink, Ukrainian President Volodymyr Zelenskiy backed Macron's warning about an escalation of the conflict: "We must ensure that Putin cannot destroy our achievements and cannot expand his aggression to other nations." (Reuters)