"Next week, I will host a meeting at the White House with two courageous leaders, President Karzai of Afghanistan and President Musharraf of Pakistan. These two leaders are working to defeat the forces of terrorism and extremism," Bush said in his weekly radio address.

The White House says next Wednesday's summit, which comes after Bush met Musharraf on Friday and meets with Karzai on Tuesday, aims to make the neighboring countries "closer allies" in the US-led war on terrorism.

The leaders were expected to take up Afghanistan's complaints that Pakistan has not done enough to halt cross-border attacks by members of the Taliban militia ousted from power by US-led forces in late 2001.

They were also slated to discuss efforts to capture or kill terrorist chief Osama bin Laden, whose al-Qaeda network carried out the September 11, 2001 attacks and led Bush to declare a global war on terrorism.

The US president, speaking to reporters after Friday's meeting with Musharraf, said it would be "an important discussion, because one of the most important avenues for peace is for Afghanistan to succeed."

On Saturday, Bush praised Musharraf for "siding with the forces of freedom and moderation and helping to defend the civilized world" and said terrorists had tried to kill the Pakistani leader "because he's working to build modern democratic institutions that could provide an alternative to radicalism."

"And it is in America's interest to help him succeed," said the US president.

Bush also hailed Karzai for doing "the work of building a safer and brighter future for his nation" and noted that more than 40 countries, including many from the Nato alliance, were trying to keep order there.