U.S. President Joe Biden and first lady Jill Biden arrived in Newquay, Cornwall, Wednesday evening in anticipation of the G-7 summit, which starts Friday.Biden kicked off his United Kingdom visit earlier Wednesday with remarks to U.S. troops stationed at Royal Air Force Mildenhall, an air force station in Suffolk. The military base is used almost exclusively by American soldiers and home to the U.S. Air Force 100th Air Refueling Wing.”Thank you. We owe you. We’re so damn proud of you,” said Biden, noting the sacrifices that service members and their families have made. “You are the solid steel spine of the United States. You are not only warriors. You are diplomats and bridge builders.”President Joe Biden speaks to American service members at RAF Mildenhall in Suffolk, England, June 9, 2021, after arriving in Europe for meetings with U.S. allies and Russian President Vladimir Putin.Biden spoke of his agenda at the G-7, NATO and European Union summits in the days ahead, as well as his meeting with Russian President Vladimir Putin next week.”I will tell Putin what I will tell him,” Biden said. ”I am going to communicate that there are consequences for violating the sovereignty of democracies in the United States, Europe and elsewhere.”The president underscored his belief that world democracies will not only endure but thrive.”We have to discredit those who believe that the age of democracy is over, as some of our fellow nations believe,” said the president, explaining that even though things are changing rapidly, democracies can still get together to reach a consensus to respond to autocrats.The first lady, speaking before Biden, showed her appreciation for military members’ sacrifice. She has recently relaunched Joining Forces, a support facility for American troops.G-7 summit goalsThe president’s main agenda in the U.K. is to attend the G-7 summit, a meeting of the world’s seven most advanced democracies: the United States, Britain, Canada, France, Germany, Italy and Japan.President Joe Biden points as he boards Air Force One, June 9, 2021, at Andrews Air Force Base, Md. Biden embarked on the first overseas trip of his term, eager to reassert the United States on the world stage and steady European allies.”Strengthening the alliance, making clear to Putin and to China that Europe and the United States are tight. The G-7 is going to move,” Biden said of his goal for the summit to reporters as he boarded Air Force One.Now Biden is under pressure to shore up a global pandemic recovery strategy with other G-7 leaders, including how to help vaccinate the world’s population. “I have one and I’ll be announcing it,” Biden said to VOA.Later, The New York Times and The Washington Post, as well as other media, cited sources familiar with the issue who said that the U.S. would buy 500 million more doses of the Pfizer COVID-19 vaccine to donate to 92 lower-income countries and the African Union over the next year. The U.S. has vaccinated more than half of its adult population, but impoverished countries are trailing far behind that level of inoculations.US planThe U.S. plan calls for the donation of 200 million doses — enough to fully vaccinate 100 million people — by the end of this year, with the remainder sent overseas in the first half of 2022, the sources said.The U.S. has just joined Asia-Pacific Economic Cooperation countries in reaffirming support for waiving vaccine patents, the so-called TRIPS waiver, at the World Trade Organization. White House press secretary Jen Psaki told VOA that negotiations on the waiver at the WTO were being pursued by U.S. Trade Representative Katherine Tai, but Psaki would not provide details on whether Biden would put his diplomatic weight behind it at the G-7.”The president has certainly spoken about his support on the waiver. He believes it’s an important component of addressing the global threat of COVID, and he will continue to play a constructive role,” Psaki said.FILE – Britain’s Prime Minister Boris Johnson meets then-U.S. President Donald Trump for talks during the G-7 summit in Biarritz, France, Aug. 25, 2019.The G-7 leaders last met in August 2019 in Biarritz, France. That summit did not produce the usual communique because of disagreements between then-U.S. President Donald Trump and other leaders on key issues. National security adviser Jake Sullivan told VOA aboard Air Force One en route to England that a communique was expected at the end of this G-7.Biden-Johnson meetingFrom Mildenhall, Biden headed to the summit’s location in Cornwall, a one-hour flight away. On Thursday afternoon, he is scheduled to meet with British Prime Minister Boris Johnson. The world will be watching how the two leaders will interact after past disagreements on policies, including Brexit, the United Kingdom’s decision to leave the EU, which the Obama-Biden administration opposed.”The chemistry hasn’t been good. President Biden had called Boris Johnson a clone of Donald Trump,” said Dan Hamilton, the director of the Global Europe Program at the Wilson Center, a global policy research group in Washington.Biden, who is of Irish descent, is also concerned that Brexit could undermine the FILE – Loyalist protesters opposed to the Northern Ireland Protocol on Brexit make their point under the statue of former Unionist leader Lord Edward Carson at Stormont, Belfast, Northern Ireland, April 8, 2021.Under the Brexit deal, Northern Ireland remains party to the EU’s single market, yet is no longer part of the union, which means a customs border must be implemented. The Biden administration wants to ensure that nothing in Brexit could endanger prospects for peace.”President Biden has been crystal clear about his rock-solid belief in the Good Friday Agreement as the foundation for peaceful coexistence in Northern Ireland. That agreement must be protected, and any steps that imperil or undermine it will not be welcomed by the United States,” Sullivan told VOA, adding that Biden would be making “statements of principle” on this issue. He would not say whether Johnson was undermining the agreement.Special tiesDespite these tensions, Hamilton said, the leaders will commit to pursuing transatlantic relations to the best of their countries’ interests. Johnson’s government has just concluded an integrated review of its foreign policy strategy, which included a reaffirmation of the special relationship between the two allies.The three-day G-7 sessions commence Friday at the Carbis Bay Hotel & Estate and Tregenna Castle Resort in St. Ives, Cornwall. The summit is expected to encounter extraordinary logistical challenges to meet COVID-19 health protocols.Steve Herman contributed to this report.