NATO's Secretary General says he regrets Russia's decision to suspend participation in its only nuclear arms control treaty with the United States. He's strongly urging Moscow to reconsider.

NATO Secretary General Jens Stoltenberg said, "Putin must not win. That would show that aggression works and force is rewarded. It will be dangerous for our own security and for the whole word."

Stoltenberg held a joint news conference on Tuesday with Ukraine's foreign minister and the EU's policy chief. He made the remark shortly after Putin warned the West over Ukraine.

The NATO chief also said Ukraine must be given what it needs to win and prevail as a sovereign nation. He added that NATO would convene a meeting of procurement experts to get Ukraine the necessary weapons.

Ukrainian Foreign Minister Dmytro Kuleba asked for support to ensure that happens.

He said his country will be moving forward to end the war as soon as possible. Kuleba also said Ukraine's victory is unavoidable.