Foreign Secretary David Miliband has insisted that the US will continue to be the UK's most important partner.
David Miliband claims there will be no change in transatlantic relations
His assertion comes after comments from two other ministers seemed to hint at a cooling of relations with the US.
"Our commitment to work with the American government in general, and the Bush administration in particular, is resolute," Mr Miliband told the BBC.
He said issues such as climate change and terrorism could only be tackled with the US.
His statement came after new Foreign Office minister Lord Malloch Brown claimed the UK and the US would no longer be "joined at the hip" on foreign policy.
And International Development Secretary Douglas Alexander warned in a speech against unilateralism and called for an "internationalist approach" to global problems.
Some analysts considered those remarks as evidence of Labour distancing itself from the US - and the close personal ties between former Prime Minister Tony Blair and US President George W Bush.
But Mr Miliband rebuffed those claims, saying: "We have a strong new leader in the United Kingdom, he is going to be a valued partner with the United States.
"He is going to work very closely with President Bush. That is the right thing to do."
Mr Miliband said Lord Malloch Brown had been reflecting on the past and saying that Britain faced a "different set of challenges than we did 10 years ago".
A strategy paper published last year by the government under Mr Blair stated that the US was the UK's single most important bilateral partner in the world, alongside its multilateral partnerships with bodies such as the UN.
Mr Miliband said nothing had changed, and that the UK and US had a "shared history and shared values".
"We want to be serious players who make a difference in the world - and you do that with the United States, not against them," he told BBC One's Sunday AM programme.
'Get a grip'
Meanwhile, former Liberal Democrat leader Lord Ashdown said the UK should use the relationship with the US to Britain's advantage.
Speaking of operations in Iraq, he said: "We have real autonomy - in fact I suspect one of Mr Blair's mistakes was he did not use the leverage he had to influence American policy."
Liberal Democrat leader Sir Menzies Campbell called on Mr Brown to "get a grip".
"What is at issue is not the relationship with the US but the nature of that relationship," he said.
"Under Tony Blair the relationship was so subordinate as to appear subservient. Britain needs to be America's candid friend not its client."
Earlier in the week, Gordon Brown told BBC Radio Five Live that he would continue to work, as Tony Blair did, "very closely with the American administration".