British Prime Minister Rishi Sunak on Saturday will call on world leaders to “double down” on support for Ukraine, saying arms and security guarantees are needed to protect the country and the rest of Europe from Russian aggression now and in the future. Sunak will deliver 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 meeting will focus on threats to the accepted rules of international relations 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 will urge 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 in excerpts released ahead of the speech. “When Putin started this war, he gambled that our resolve would falter. Even now he is betting we will lose our nerve.” Sunak will also call 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 the peace since the end of World War II, Sunak is expected to say. “It’s about the security and sovereignty of every nation,” Sunak says in the excerpts. “Because Russia’s invasion, its abhorrent war crimes and irresponsible nuclear rhetoric are symptomatic of a broader threat to everything we believe in.”