Biden meets with UK's Sunak, Charles King III ahead of NATO meeting

United States President Joe Biden began his trip to Europe on Monday with a visit to London where he met with British Prime Minister Rishi Sunak and King Charles-III

The US President described the relationship between the two nations as "rock solid."

The meeting between Biden and Sunak comes ahead of a key NATO meeting in Vilnius, Lithuania's capital.

Biden, who is on a three-nation visit, made his first stop at the UK before heading later in the day for a NATO leaders summit in Lithuania.

In the UK, the President first sat down with PM Sunak at his No. 10 Downing Street residence.

At the meeting, Biden said, "We met in San Diego, Belfast, Hiroshima, Washington, here. And couldn't be meeting with a closer friend and a greater ally. And we got a lot to talk about, and I -- I think we're doing well. I think we're moving along in a way that's positive, but our relationship is rock solid between the United States, Great Britain. And I look forward to our discussions," according to the statement released by the White House.

PM Sunak welcomed Biden and said, "Very privileged and fortunate to have you here."

Recalling the previous meeting at the White House in June when UK and US signed the Atlantic Declaration -- the first-of-its-kind economic partnership, Sunak said, "Great for us to carry on our conversations, which we were having just a month or so ago, it feels like, in the White House, where we signed the Atlantic Declaration -- the first-of-its-kind economic partnership, which I know we'll be talking about today: how do we strengthen our cooperation, joint economic security to the benefit of our citizens."

The UK PM further stated that after this they will head to NATO in Vilnius, and will do everything they can to strengthen Euro-Atlantic security. Sunak hailed the UK and the US as "two of the firmest allies" in Nato, according to the statement.

Later on, Biden met King Charles III at Windsor Castle with 23 leading philanthropists and financiers to help catalyze finance to support emerging markets and developing countries in tackling the climate crisis.

After this, the gathering followed the Climate Finance Mobilization Forum, which was convened by the UK Energy Security and Net Zero Secretary Grant Shapps and US Special Presidential Envoy for Climate John Kerry, and inspired by the work of the King.

"Today's gathering builds on longstanding UK-US efforts to turbocharge the net zero, resilient transition already underway in developing and emerging economies on the road to COP28," the statement read.

"The Forum brought together key players to identify how we can go further faster to mobilize the private investment needed to expand clean and renewable energy across the globe, reduce both potent CO2 and non-CO2 emissions, halt deforestation and restore forests, and build resilience to a changing climate," it added.

In the three-nation visit, Biden will travel on to Vilnius, Lithuania, on Monday night and hold talks with NATO leaders there on Tuesday and Wednesday.

On the agenda of the NATO summit, alliance leaders will discuss the conflict in Ukraine.

Biden's last stop will be in Helsinki for talks with the leaders of the newest NATO member, Finland, and to attend a summit of US and Nordic leaders.