Britain said it would provide a further 1.3 billion pounds ($1.60 billion) in military support and aid to Ukraine, making the pledge ahead of a planned video call on Sunday by Group of Seven leaders with Ukrainian President Volodymyr Zelensky.
UK Prime Minister Johnson has been one of the strongest supporters of Ukraine's efforts to resist Russian forces since the start of the Ukraine war on Feb. 24. Johnson's government has sent anti-tank missiles, air defence systems and other weapons to Ukraine.
The leaders of the G7 countries - Britain, Canada, France, Germany, Italy, Japan and the United States - will hold their virtual meeting with Zelensky on Sunday, the day before Russia marks its Victory Day holiday, which marks the end of World War Two in Europe.
Britain said the extra spending on Ukraine will come from a reserve used by the government for emergencies.
The government also said Johnson will host a meeting of leading defence companies later this month to discuss increasing production in response to the increased demand created by the Ukraine war.