Joe Biden has arrived in the UK on Air Force One ahead of the G7 summit in Cornwall.
He touched down at RAF Mildenhall in Suffolk on Wednesday evening, beginning his first overseas trip as US president.
A large crowd of US Air Force personnel and their families were waiting for him inside a hangar, where he addressed them.
He said: “At every point along the way we are going to make it clear that the United States is back and democracies of the world are standing together to tackle the toughest challenges and the issues that matter most to our future.”
The UK and US, as founding members of NATO, were part of “the strongest military and political alliance in the history of the world”, he said.
“Now we need to modernise our alliance, investing in our critical infrastructure, our cyber capabilities and to keep us secure against every threat we’ve faced over the last decade, and the new challenges we are about to face as well.”
After his time at Mildenhall, Mr Biden flew to Newquay before travelling on to Tregenna Castle in Carbis Bay.
He will meet Prime Minister Boris Johnson tomorrow before the G7 begins in Carbis Bay on Friday.
After the summit – which also includes leaders from Canada, Japan, France, Germany, and Italy – Mr Biden and the first lady will meet the Queen at Windsor Castle before the president meets NATO leaders in Belgium and then Russian President Vladimir Putin in Switzerland.
Speaking about his meeting with Mr Putin, Mr Biden said the US was not seeking conflict but would respond in a “robust and meaningful way” if Russia engaged in harmful activities.
Mr Johnson has said he wants to discuss the COVID-19 pandemic and urge other leaders to do more to vaccinate the rest of the world, but it is likely the growing Brexit trade row and its effect on the Northern Ireland peace process will also come up.
Mr Biden’s national security adviser Jake Sullivan has warned that the president has “very deep” concerns on the issue, adding that the post-Brexit Northern Ireland Protocol is “critical” to ensuring that the Good Friday Agreement is protected.
During Mr Biden’s flight across the Atlantic, his press secretary Jen Psaki and Mr Sullivan told reporters what else is on Mr Biden’s agenda:
• Boosting vaccine supply – the US announced on Wednesday evening that it would donate 500 million COVID-19 vaccines to poorer countries
• Following discussions about possible waivers of intellectual property laws allowing more vaccines to be produced around the world, Mr Sullivan said he does not anticipate contention but “convergence” on the issue
• Mr Sullivan said that moves to vaccinate poorer countries faster are “the right thing to do” and the smart thing to do in terms of stopping new variants of the virus. Mr Biden also wants to show that democracies can lead the fight
• Mr Biden will meet Russian president Vladimir Putin in Switzerland where he will discuss the rise in ransomware attacks that have been attributed to Russian hackers
• The conflict in Syria will be discussed, as will concerns about Russia’s new nuclear systems
• Mr Biden and Mr Johnson are expected to refresh the Atlantic Charter. The charter was first announced in 1941 by the US and UK, setting out a vision for the post-war world