On the eve of his first visit to Washington as British prime minister, Gordon Brown said relations between the two allies would always be strong. But his government has signaled that it may not have as cozy a relationship with the US as that of predecessor Tony Blair. Since Brown came to power a month ago, he has taken a number of steps seen as signs that his government's relationship with the Bush administration would be different - notably by appointing an outspoken critic of the Iraq war to his Cabinet. "We know that we cannot solve any of the world's major problems without the active engagement of the US," Brown said in a statement Saturday night. "The relationship between an American president and a British prime minister will always be strong," he said. "I am looking forward to my meeting with President Bush to discuss how we can work together to meet many of the great challenges we face." Brown heads to Washington on Sunday - his first major overseas visit since ending his 10-year wait to succeed Blair last month. He will hold talks with Bush at his Maryland retreat, Camp David, and deliver a speech to the United Nations in New York following talks with UN Secretary-General Ban Ki-moon. Brown must contend with inevitable comparisons to Blair. The former prime minister's close bonds with Bush and predecessor Bill Clinton won him admiration in the United States but cost him popularity at home, especially with regard to his decision to back the Iraq invasion. White House press secretary Tony Snow said Thursday that Bush and Brown have a "very special important relationship." But some of Brown's moves as premier have raised eyebrows in Washington. He named Mark Malloch-Brown as junior foreign affairs minister. As deputy to ex-UN General Secretary Kofi Annan, Malloch-Brown had fierce spats with former US ambassador John Bolton. Malloch-Brown has said Bush and Brown would not be "joined at the hip," anther signal that Britain could be seeking some distance from Washington. British commentators also interpreted a speech in Washington by new International Development Secretary Douglas Alexander as a subtle critique of Bush's policies. Alexander called for end to a world in which "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. Brown also offered a post to John Denham - an ex-minister who quit the government in 2003 in protest over Iraq. Brown's office denied a report in the Independent newspaper that Brown's visit had been rushed forward from a planned date in September to reassure Washington. In many ways, Brown knows the United States better than Blair. While Blair took family holidays in Italy and France, Brown prefers Cape Cod. Alan Greenspan, the former Federal Reserve chairman, is a respected economic adviser to Brown. But Reginald Dale, a senior fellow at the Washington-based Center for Strategic and International Studies, said it was unlikely Brown could recreate Blair's close relationship with Bush. "Most people here acknowledge things won't be the same," said Dale. "It will be amicable, but not as intense as Bush's relationship with Blair, which was something quite unique." While Bush and Blair were "in tune, they were soulmates on the most important strategic and political issues of the day," Brown is likely to prove more cautious and pragmatic, Dale said. Brown arrives with some thorny issues in his policy folder, not least the fate of Britain's remaining soldiers in Iraq. Britain has 5,500 troops in the country, based almost entirely on the fringes of the southern city of Basra. Military chiefs in London have said Britain is likely to hand over control of Basra to local forces by the end of the year, a move certain to spark a domestic clamor for more British troop withdrawals. Brown will discuss with Bush Britain's likely role in aiding the US plan to deploy a missile defense system in Europe, his Downing Street office said. Britain has said Menwith Hill, a U.S. military listening station in northern England, would be equipped with communications equipment enabling it to route satellite warnings about missile launches to British and American officials. Downing Street said the leaders would also examine a potential role for Britain in a Middle East peace conference in the U.S., which Bush has called and said would likely be held in September. They also will discuss the Iran nuclear controversy, the eventual status of Kosovo and the humanitarian crisis in Darfur, officials said.