British Prime Minister Rishi Sunak pledged Monday to increase U.K. military funding by 5 billion pounds ($6 billion) over the next two years in response to Russia’s invasion of Ukraine and the “epoch-defining challenge” posed by China.

The increase, part of a major update to U.K. foreign and defense policy, is less than military officials wanted. Sunak said the U.K. would increase military spending to 2.5% of gross domestic product “in the longer term,” but did not set a date. Britain currently spends just over 2% of GDP on defense, and military chiefs want it to rise to 3%.

The extra money will be used, in part, to replenish Britain’s ammunition stocks, depleted from supplying Ukraine in its defense against Russia. Some will also go towards a U.K.-U.S.-Australia deal to build nuclear-powered submarines.

Sunak will meet U.S. President Joe Biden and Australian Prime Minister Anthony Albanese in San Diego on Monday to confirm next steps for the military pact, known as AUKUS, struck by the three countries in 2021 amid mounting concern about China’s actions in the Pacific.

Britain last produced a defense, security and foreign policy framework, known as the Integrated Review, in 2021. The government ordered an update in response to an increasingly volatile world. Russia’s February 2022 invasion of Ukraine upended European security, and the U.K. is also increasingly concerned about what the government calls “the epoch-defining challenge presented by the Chinese Communist Party’s increasingly concerning military, financial and diplomatic activity.”

Britain’s intelligence agencies have expressed growing concern about China’s military might, covert activities and economic muscle. Ken McCallum, head of domestic spy agency MI5, said in November that “the activities of the Chinese Communist Party pose the most game-changing strategic challenge to the U.K.”