New Delhi: Ahead of NATO Summit, US President Joe Biden on Monday met Britain's King Charles to discuss climate issues, reported news agency Reuters. Biden arrived in Britain before departing for Lithuania for a NATO summit, at which allies aim to show solidarity with Ukraine against Russia's invasion while not yet accepting Kyiv as an alliance member.


Earlier in the day, he had met Prime Minister Rishi Sunak and hailed the "rock-solid" friendship with a close ally.


"Great for us to carry on our conversations," Sunak told Biden as they sat in the Downing Street garden.


"We’ve got a lot to talk about," Biden replied, adding, “Our relationship is rock-solid. Couldn’t be meeting with a closer friend and a greater ally. We've got a lot to talk about."


Biden's visit to the UK comes amid concerns among US allies over its decision to send cluster bombs to Ukraine amid its war with Russia.


After meeting Sunak, Biden headed to Windsor Castle to meet the king, the higher-profile part of his short British trip.


The king greeted the president in the quadrangle of the castle, where he was given a guard of honour.


Biden was expected to discuss climate change in Windsor, according to Reuters.


As per the agency, the men were due to have tea before discussing how to help boost private investment to combat climate change, a threat both leaders say is existential.


"The president has huge respect for the king's commitment on the climate issue in particular. He has been a clarion voice on this issue," White House national security adviser Jake Sullivan told reporters aboard Air Force One on Sunday.


The 74-year-old King Charles has campaigned and spoken about the topic for over five decades now. Biden and King Charles had previously met at COP 26 in 2021, where the King praised Biden's leadership on the said topic by saying "We need you badly."



Biden and Sunak will then head to Lithuania where they will gather along with other NATO leaders for a key summit.


The US President is then expected to travel to Helsinki where he will be meeting with some Nordic leaders.