''We speak today in the shadow of terrorism, but it will not obscure what we came here to achieve,'' said British Prime Minister Tony Blair, the summit host, at the end of the three-day gathering.

``It is in the nature of politics that we do not achieve absolutely everything we hope to achieve, but nonetheless I believe we have made very substantial progress indeed,'' he said.

With a last-minute pledge from Japan, Blair won a key victory from world leaders, announcing that aid to Africa would rise from US$25 billion (HK$195 billion) now to US$50 billion.

In a separate joint statement, the leaders pledged ``new joint efforts'' to combat terrorism in light of the deadly bombings in London Thursday.

Among those commitments is cooperating in ways to improve the safety of rail and subway travel.

``We will work to improve the sharing of information on the movement of terrorists across international borders, to assess and address the threat to the transportation infrastructure and to promote best practices for rail and metro security,'' the declaration said.

Blair ticked off a list of accomplishments from a meeting that nonetheless produced less than he had hoped.

Aside from the massive increase in aid for Africa, leaders signaled support for new deals on trade, canceled the debt of some of the world's poorest nations, pledged universal access to AIDS treatment, committed to a peacekeeping force in Africa and heard African leaders promise to move toward democracies that follow the rule of law.

Blair also announced an aid deal of up to US$3 billion for the Palestinian Authority over coming years - which would allow ``two states, Israel and Palestine, two peoples and two religions [to] live side by side in peace.''

G8 leaders also agreed to begin a new dialogue on climate change with emerging economies, including Brazil, Mexico, China, South Africa and India. The first meeting is to be held in Britain November 1.

But Blair said the United States must join the campaign to reduce greenhouse gas emissions if huge emerging economies such as China and India are also expected to participate.

French President Jacques Chirac said Thursday the agreement on climate change is ``important, even if it doesn't go as far as I would have wanted it to.''

But he called the compromise language a ``visible, real evolution'' in the American position.

France and others were hoping to include an explicit reference in the declaration to the Kyoto Protocol and how to proceed when it expires in 2012. But reference to the accord was minimal.

The Climate Group, WWF International and Friends of the Earth International said the G8 has failed to take real action against a serious problem. ASSOCIATED PRESS