US President Joe Biden meets UK Prime Minister Rishi Sunak at 10 Downing Street. (Photo: The Guardian)

The two leaders discussed the upcoming NATO summit, the Ukraine conflict, and the Atlantic Declaration on economic partnership they launched last month to strengthen the economic and trade security relationship between the two countries.

In response to the US decision to send Ukraine cluster munitions, Sunak said that Britain adheres to its obligations under the Convention on Cluster Munitions, which involve discouraging the use of such weapons. However, the decision is for each country to make, he said.

After the meeting, Biden went to Windsor Castle to meet King Charles III. They met with delegates from the US-UK Financing Forum, which was hosted by UK Energy Secretary Grant Shapps and the US President's Climate Envoy John Kerry to discuss measures to boost private investment in combating climate change.

Biden arrived in London on Saturday, kicking off a three-nation visit, with the final destination being Finland, the newest member of NATO.