NATO Secretary General Jens Stoltenberg claimed that a steady flow of Western weapons was vital for any peace in Ukraine, after a summit confirmed Ukraine's refusal to give in to Russia's demands.
"It may seem like a paradox, but the path to peace is more weapons for Ukraine," Mr Stoltenberg said at the Wilson Centre on a visit to Washington.
He also called for China to face consequences if it keeps supporting Russia, accusing Beijing of worsening the Ukraine war while seeking better relations with the West.
"Beijing cannot have it both ways. At some point - and unless China changes course - allies need to impose a cost. There should be consequences," Mr Stoltenberg added.
It comes as Russia said a Kyiv-led international peace summit on Ukraine produced "zero" results.
Officials from more than 90 countries gathered in Switzerland this weekend, backing Ukraine's independence but leaving key questions of how to end the conflict unresolved.
Russia was not invited to the summit.
"If we talk about the results of this meeting, then they come down to zero," Kremlin spokesman Dmitry Peskov said.
A final document was backed by a vast majority of countries attending the summit, but several countries did not sign it, including Saudi Arabia, India and the United Arab Emirates.
"Many countries understood the lack of perspective of any serious discussion without the presence of our country," Mr Peskov said.
He said Russian President Vladimir Putin was "still open to dialogue and serious discussion".
Last week, Mr Putin said that Russia was willing to end the war, but he set out conditions for Ukraine -renouncing its NATO ambitions and withdrawing troops from four regions claimed by Russia - that Kyiv rejected as tantamount to capitulation.
The Kremlin launched its full-scale offensive against Ukraine on 24 February 2022.
