US President Joe Biden has begun his first trip abroad since taking office by hailing America's unwavering commitment to the NATO alliance and warning Russia it faced "robust and meaningful" consequences if it engaged in harmful activities.
Biden, speaking to about 1000 troops and their families at a British air base, said he would deliver a clear message to Russian President Vladimir Putin when they met next week after separate summits with NATO, G7 and European leaders.
"We're not seeking conflict with Russia," the Democratic president said at the start of his eight-day visit to Europe.
"We want a stable and predictable relationship ... but I've been clear: the United States will respond in a robust and meaningful way if the Russian government engages in harmful activities."
Biden has said he was determined to rebuild trans-Atlantic ties and reframe relations with Russia after four rocky years under Republican former president Donald Trump, whose tariffs and withdrawal from treaties strained relations with major allies.
"This is my first overseas trip as president of the United States. I'm heading to the G7, then the NATO ministerial and then to meet with Mr Putin to let him know what I want him to know," Biden said, drawing cheers from the troops.
"At every point along the way, we're 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."
Biden told reporters as he left for Europe that his goals were "strengthening the alliance, making it clear to Putin and to China that Europe and the United States are tight".
His summit with Putin on June 16 in Geneva is the capstone of the trip, an opportunity to raise US concerns directly with the Russian leader about ransomware attacks emanating from Russia, Moscow's aggression against Ukraine and a host of other issues.
Speaking to US troops based at Royal Air Force Mildenhall base, Biden underscored the US commitment to the NATO alliance but said it needed to modernise and expand its cyber capabilities.
Biden also comes to Europe with a goodwill gesture: the planned announcement that the United States will buy and donate 500 million Pfizer coronavirus vaccine doses to about 100 countries during the next two years.
The United States has faced criticism over securing access to much of the initial stockpile of the most promising vaccines.
Biden's first stop of the trip is the seaside village of St Ives in Cornwall, where he will take part in the G7 summit.
The meeting is expected to be dominated by vaccine diplomacy, trade, climate and an initiative for rebuilding infrastructure in the developing world.
US officials see that effort as a way to counter China's growing influence.
Biden will have a meeting with British Prime Minister Boris Johnson on Thursday in Cornwall, where he will bring an uncomfortable message: stop heated EU divorce negotiations from undermining a 1998 US-brokered Good Friday Agreement that ended three decades of bloodshed in Northern Ireland.
"President Biden has been crystal clear about his rock-solid belief in the Good Friday Agreement as the foundation for peaceful co-existence in Northern Ireland," White House national security adviser Jake Sullivan told reporters aboard Air Force One.
After three days of G7 summitry, Biden and his wife, Jill, will visit the Queen at Windsor Castle.