The G8 conference, which begins today at a heavily guarded resort in Gleneagles, Scotland, has become a focal point for activists, religious leaders and rock stars who want wealthy nations to do more to help the world's poor and combat global warming.

British Prime Minister Tony Blair, the G8 chairman and summit host, has served notice that aid to Africa and limits on greenhouse gas emissions are at the top of his agenda, and he wants Bush to make bigger commitments on both issues.

For Bush, the summit is an opportunity to repair America's battered image among allies who perceive his administration as unilateralist, self-interested and stingy. For Blair, whose domestic popularity has plummeted in part because of his support for the US-led war in Iraq, it is a chance to show that he is willing to stand up to Bush, at least rhetorically.

In the days leading up to the summit, as rocker Bob Geldof orchestrated ``Live 8'' concerts in 10 cities and thousands of activists began gathering in Edinburgh, Scotland, the president and his advisers did their best to dispel the image of Bush as global cowboy. ``I understand we have an obligation as an influential nation to reach out to others,'' Bush said in an interview with the Danish Broadcasting Corp.

``We also have an obligation as an influential nation to help others,'' he said, alluding to Blair's emphasis on Africa.

Bush made those remarks shortly after announcing his administration's plans to double development aid to Africa by 2010, but not in the way Blair and other G8 members have proposed. Bush is also expected to rebuff Blair's efforts to secure a commitment to consider mandatory curbs on greenhouse gases.

Some Africa advocates said although the president's pledge is welcome, it departs substantially from what some allies are seeking. ``Bush's position on this, like on many other issues, is `My way or the highway,''' said Susan Rice, former assistant secretary of state for African affairs in the Clinton administration. ``We'll do it on our terms at our pace and through our own mechanisms. We won't engage in multilateral endeavors on this, even when our best friend Tony Blair asks us to.''

The result, said Rice, is to ``reinforce perceptions of American exceptionalism and unilateralism,'' rather than repair America's reputation as an international maverick.

Recent opinion polls in other countries show just how widespread those perceptions have become.

A survey of global attitudes conducted in May by the Pew Research Center showed that in 12 of 16 nations, substantial majorities view US foreign policy as fundamentally self-serving.

Bush said last week he understands why some Europeans did not agree with his decision to wage war in Iraq. But he offered no apology for his decision to proceed without their endorsement.

``People have got to understand my mentality,'' he said. ``It changed after September 11. For some in Europe, September 11 was just a moment, a sad moment. For me, it changed the way I looked at the world, and changed how many Americans looked at the world because we were attacked.''

White House officials say Bush hopes to use the summit as a forum for the United States to forge consensus on important issues, including Africa aid, climate change, energy policy, Middle East peace and the war on terrorism.

In a flurry of activity designed to showcase concern about the estimated 300 million Africans living in extreme poverty, Bush announced his pledge to double US aid from US$4.3 billion (HK$33.54 billion) a year in 2004 to at least US$8.6 billion in 2010, including a new US$1.2 billion program to combat malaria and smaller initiatives to expand education and deter sexual violence and abuse against women.

The administration has already endorsed a plan developed by G8 finance ministers to write off about US$40 billion in debt owed by 18 poor countries, including 14 in Africa. The deal is expected to reduce their debt payment obligations by about US$1 billion annually.

Bush's promise to double aid was met with near-universal applause, yet there was some grumbling. Some Africa advocates said it is mainly a repackaging of earlier commitments that have been underfunded by Bush and Congress, and falls short of the kind of commitment needed to help sub-Saharan Africa achieve the United Nations' Millennium Challenge goal of cutting poverty in half by 2015.

Bush has rejected a British proposal to participate in an international bond issue to finance Africa aid and has refused to join other G8 countries in a pledge to increase overall public development assistance to 0.7 percent of gross domestic product by 2015. The United States devotes 0.16 percent of GDP to foreign aid, placing it 21st on a list of 22 wealthy nations.

Bush administration officials said the 0.7 percent standard was not appropriate for America because of the size of the US economy and the substantial tax-sheltered flow of private contributions to relief organizations. ``If we did 0.7 percent, the aid budget would go from US$19 billion to US$91 billion. We couldn't spend that money if we wanted to,'' says Andrew Natsios, administrator of the US Agency for International Development.

If the United States attempted to meet Blair's challenge, it would be accused of dispensing ``imperial aid'' that might swamp the efforts of other countries and the World Bank, he said.

Still, development advocates and foreign policy analysts said Blair might be satisfied with Bush's promise to double assistance, which appears to match for now a separate British proposal to increase global development aid to the continent from about US$25 billion a year in 2003 to US$50 billion in 2010 and US$75 billion in 2015.