Britain's Prime Minister Rishi Sunak leaves 10 Downing Street to go to the House of Commons for his weekly Prime Minister's Questions in London, March 1, 2023. (PHOTO / AP)

SAN DIEGO – Prime Minister Rishi Sunak will spend an extra 5 billion pounds ($6 billion) to replenish ammunition stocks and fund the next phase of a submarine pact with the United States and Australia in an update to Britain's foreign policy framework.

With his government unveiling the update to Britain's national security and international policy, Sunak, on a visit to the US, will also set out an "ambition" to increase defense spending to 2.5 percent of gross domestic product in the longer term.

Sunak is under pressure at home to offer more help to the defense ministry to combat the impact of inflation and spur production of ammunition and other military hardware to replace weapons sent to Ukraine

Sunak hailed the move as a way "to ensure we are never again vulnerable to the actions of a hostile power", but his offer of 5 billion pounds is less than half of what some in his governing Conservative Party say is needed to be able to support Ukraine, while not leaving Britain vulnerable.

He said his previous increases to defense spending showed he was a man of his word, and described the new commitments as a "strong and positive statement".

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"As the world becomes more volatile and competition between the states becomes more intense, the UK must be ready to stand our ground," he said in a statement.

"We will fortify our national defenses, from economic security to technology supply chains and intelligence expertise, to ensure we are never again vulnerable to the actions of a hostile power."

The Ministry of Defence said minister Ben Wallace was "delighted" with the settlement, especially in the tough economic times, and said it would maintain the upward trajectory after the government invested heavily in recent years.

The unveiling of the updated Integrated Review has been choreographed to coincide with Sunak's visit to San Diego to agree the next steps in a landmark defense agreement, AUKUS, with the United States and Australia.

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Sunak is under pressure at home to offer more help to the defense ministry to combat the impact of inflation and spur production of ammunition and other military hardware to replace weapons sent to Ukraine.

Britain and other Western countries have scaled up their pledges of military aid for Ukraine this year, with promises of tanks and armored vehicles, as well as longer-range weapons. London has also offered to train Ukrainian soldiers on fighter jets.