The Japanese and the British prime ministers have agreed to denounce plans by pro-Russian secessionists to hold referendums in some Ukrainian regions.
Kishida Fumio and Liz Truss held talks for about an hour in New York on Tuesday on the sidelines of the United Nations General Assembly.
Kishida expressed his condolences on the passing of Queen Elizabeth II. Truss thanked him for the sympathy from the people of Japan.
Regarding the Ukraine situation, the two leaders agreed that it is important for the international community to unite in continuing sanctions on Russia and support for Ukraine.
They agreed that the pro-Russian separatists' plan to hold referendums on joining Russia is unacceptable. The votes are planned later this month in the separatist-controlled territories in four regions of Ukraine.
Kishida and Truss said the move will further undermine Ukraine's sovereignty and territorial integrity.
The Japanese and British leaders also shared serious concerns about unilateral attempts to change the status quo by force in the East and South China seas. China is growing its military presence there.
They also agreed to continue to work together on North Korean issues, such as its nuclear and missile programs and abductions of foreign nationals including Japanese citizens.