US President <a href="https://www.thenationalnews.com/tags/joe-biden/" target="_blank">Joe Biden</a> met King Charles III at Windsor Castle on Monday as part of a whistle-stop visit to London before heading to a Nato summit in Lithuania. Though it was not a full-blown state visit, it had all the trappings of one. Mr Biden was treated to a display of pageantry as he arrived on the grounds of the historic royal residence before sitting down for 20 minutes together in the private Windsor Castle sitting room for tea and an exchange of gifts, then viewing US-related items from the Royal Collection. He and the king held a meeting on climate action, which was attended by Dr Sultan Al Jaber, UAE Minister of Industry and Advanced Technology and President-Designate of Cop28, and other high-profile guests, including US climate change envoy John Kerry and Grant Shapps, UK Secretary for Energy Security and Net Zero. King Charles, who was crowned in May, has already made the environment a significant part of his policy legacy and has long fought to protect wildlife and battle climate change. Mr Biden has also identified climate change as one of the four crises he was determined to confront during his time in office and committed $375 billion in climate-related incentives last year. Mr Biden’s whirlwind visit to the UK was a layover in London on the way to the Nato summit in Vilnius, Lithuania. It began with a meeting with Prime Minister Rishi Sunak in Downing Street, with the American leader hailing the “rock-solid” relationship between the US and the UK. The American leader then headed to Windsor on the Marine One helicopter and was then driven to the castle's main quadrangle, where he was greeted by the king. He received a royal salute and heard the US national anthem courtesy of the band of the Welsh Guards. Mr Biden, accompanied by the king, walked on the grass of the quadrangle to inspect the guardsmen, who stood in two rows. After tea, they met members of a climate finance mobilisation forum, at which finance and philanthropic leaders discussed the support they can offer to lower-income nations The pair hoped that the meeting would encourage private companies to do more to bolster clean energy in developing countries. During the climate meeting, Mr Shapps said he was “enormously pleased” that the US Inflation Reduction Act had helped advance clean energy goals. Mr Kerry added that the world is in “unchartered territory”. The UK government said more than $1 trillion is needed by 2030 to help developing economies get on track to reach net-zero carbon emissions by 2050. Additional investment, including from the private sector, is required to cut non-CO2 emissions, halt deforestation and adapt and build resilience to climate change. The meeting at Windsor Castle was their first since September, when King Charles ascended the throne. Mr Biden was in attendance at the Heads of State Reception at Buckingham Palace the evening before he and his wife attended Queen Elizabeth II's funeral service. They had previously met at the G7 Leaders Summit in June 2021 and Cop26 in Glasgow later that year. They shared a handshake at Cop26 and Mr Biden expressed his admiration for the king's passion for environmental activism. Mr Biden did not attend King Charles’s coronation, sending first lady Jill Biden to attend in his place. Earlier, Mr Biden visited Downing Street, where he met UK Prime Minister Rishi Sunak for discussions on Ukraine and security. Mr Sunak said the pair would continue talks on how the UK and US can “strengthen our co-operation, our joint economic security, to the benefit of our citizens”. A spokesperson for the King said about the Windsor Castle event: “An extremely cordial and successful meeting that touched on a wide variety of issues of mutual interest and concern." Mr Biden, who arrived in the UK on Air Force One late Sunday, is heading to the Lithuanian capital, Vilnius. He left for the two-day Nato meeting after spending under two hours at Windsor. From there, he heads to Finland, Nato's newest member, for a US-Nordic Leaders' Summit.