Rishi Sunak will meet President Joe Biden in the US on Monday as ministers unveil the new integrated review of defence and foreign policy.
The Prime Minister’s Australian counterpart Anthony Albanese will join the pair in San Diego for talks over the procurement of nuclear-powered submarines under the Aukus pact between the three nations.
While in the US, Downing Street confirmed Mr Sunak will make an announcement surrounding the integrated review which was being updated in the wake of Russia’s invasion of Ukraine.
The Prime Minister’s official spokesman said: “I can say the Prime Minister will be in the US on Monday for discussions on Aukus with President Biden and the Australian Prime Minister Albanese.
“On Monday the Government will also publish the update to the integrated review of security, defence, development and foreign policy.”
Mr Sunak’s first visit to the US while Prime Minister will come in another crucial week during his leadership, with the Budget also coming on Wednesday.
Defence minister James Heappey acknowledged there has been “robust” public and private clashes between the Ministry of Defence and Treasury over funding levels.
Defence Secretary Ben Wallace has been arguing for a multi-billion hike to his budget.
San Diego, in the state of California, where Mr Sunak used to live, is home to the US Pacific Fleet.