Starmer told a news conference that "our long-term national interest requires closer partnership with our allies in Europe and with the European Union".

The British prime minister has sought to rebuild post-Brexit relations with the EU since winning power in July 2024, hoping to fire up Britain's insipid economy.

He cited the "volatile" Middle East and the "deep damage" caused by Brexit, 10 years after the referendum in favour.

"The opportunities to strengthen our security and cut the cost of living are simply too big to ignore," Starmer said.

He made the speech at a rocky time for Britain's "special relationship" with the United States, as President Donald Trump has made repeated criticisms of Starmer for his support for the US-Israel war against Tehran.

Trump has said the United States will reduce its role within NATO, while Starmer on Wednesday insisted the bloc is the world's "most effective military alliance".

The prime minister insisted that he was "not going to choose" between good relations with the US or the EU, saying "it is in our interest to have a strong relationship" with both.

"But I do think that when it comes to defence and security, energy emissions, and the economy, we need a stronger relationship with Europe," he said.

At a planned summit with the EU in Brussels this year, Britain will seek agreement on "more ambitious" goals of "closer economic cooperation" and "closer security cooperation", the prime minister said.

Britain and the EU held a first bilateral summit last year.

Starmer said that Britain and the EU need "a partnership for the dangerous world that we must navigate together".