Downing Street has denied claims a speech by a Cabinet minister was critical of US foreign policy.
Douglas Alexander delivered the speech in Washington DC
Speaking in the US, International Development Secretary Douglas Alexander emphasised the need for "new alliances, based on common values".
He warned against unilateralism and called for an "internationalist approach" to global problems.
Asked if this amounted to criticising the US, Gordon Brown's spokesman said that view "was not shared" by the PM.
He said Mr Alexander had given "a fairly straightforward speech on development".
It was "not some startling new insight", the spokesman said, adding that the "interpretation", rather than the "content" had been the problem.
Correspondents have described the speech as a "coded criticism" of the policies of President George W Bush.
Earlier, Mr Brown told BBC Radio 5 Live: "We will not allow people to separate us from the United States of America in dealing with the common challenges that we face around the world.
"I think people have got to remember that the relationship between Britain and America and between a British prime minister and an American president is built on the things that we share, the same enduring values about the importance of liberty, opportunity, the dignity of the individual.
"I will continue to work, as Tony Blair did, very closely with the American administration."
Mr Alexander's speech came as the Democratic-controlled House of Representatives voted in favour of pulling most combat troops out of Iraq by April next year.
The vote happened despite President Bush's threat to veto any timetable for withdrawal.
In his address to the Council on Foreign Relations in Washington DC, Mr Alexander said isolationism "simply does not work in an interdependent world".
"In the 20th Century a country's might was too often measured in what they could destroy. In the 21st Century strength should be measured by what we can build together," he said.
"And so we must form new alliances, based on common values, ones not just to protect us from the world, but ones which reach out to the world.
"There is no security or prosperity at home unless we deal with the global challenges of security, globalisation, climate change, disease and poverty. "We must recognise these challenges and champion an internationalist approach - seeking shared solutions to the problems we face.
"Multilateralist, not unilateralist means a rules-based international system. Just as we need the rule of law at home to have civilisation so we need rules abroad to ensure global civilisation."
Mr Alexander, who is seen as one of Prime Minister Gordon Brown's closest allies, also said "empowering women must be a priority for us all".
He said: "The economic, social and political position of women in many countries is actively preventing us from reducing child and maternal mortality, and stopping the spread of HIV/Aids."
Mr Alexander said winning support for this approach was "not easy" and work had to be done to make them "the accepted norm".
He said: "This means persuading political leaders, indeed community leaders, faith leaders and civic leaders to actively support these principles - whether they are in Europe or the US, China, India or South Africa."
Mr Alexander also called for "core values" of "opportunity, responsibility and justice" to tackle global poverty.
BBC correspondent James Westhead said the speech appeared to suggest that Britain was distancing itself from US President George W Bush.
Our correspondent said: "Some observers have interpreted this as a coded criticism of a president seen by some as high-handed and unilateralist."
But Mr Alexander stressed to the BBC that Gordon Brown had already spoken to the president and was committed to a strong and effective dialogue.
He said he made "no apology for speaking forcibly about the need for the whole international community to work together to tackle international poverty".
Liberal Democrat foreign affairs spokesman Michael Moore said: "Douglas Alexander's comments may hint at a fresh relationship with the United States.
"However, the prime minister's hasty efforts to play down the speech only remind us that this is the man who signed the cheques for the Iraq war."