MUNICH (AP) — British Prime Minister Rishi Sunak called on world leaders Saturday to “double down” on support for Ukraine, saying additional arms and security guarantees are needed to protect the country and the rest of Europe from Russian aggression now and in the future.

Sunak delivered the message in a speech to the Munich Security Conference, an annual meeting of heads of state, defense ministers and other world leaders. This year’s conference is focused on threats to the accepted rules of international relations nearly a year after Russian troops invaded Ukraine.

Highlighting Britain’s recent commitment to provide battle tanks, advanced air defense systems and longer-range missiles to Ukraine, Sunak urged other nations to follow suit before Russia launches an expected spring offensive.

“Now is the moment to double down on our military support,” Sunak said. “When Putin started this war, he gambled that our resolve would falter. Even now he is betting we will lose our nerve.”

Sunak also called on NATO to provide long-term security guarantees for Ukraine. Such commitments are necessary to shield Ukraine from future Russian aggression and to protect the system of international rules that have helped keep peace since the end of World War II, Sunak said.

“It’s about the security and sovereignty of every nation,” the prime minister said. “Because Russia’s invasion, its abhorrent war crimes and irresponsible nuclear rhetoric are symptomatic of a broader threat to everything we believe in.”