Talks between President George W Bush and Afghan President Hamid Karzai will focus on worsening violence in Afghanistan and the threat from militant hideouts across the border in Pakistan.

Bush's two-day meeting with Karzai at the Camp David retreat in the Maryland mountains comes as the US president has found himself on the defensive over the troubled effort to rebuild Afghanistan and the failure to find al Qaeda leader Osama bin Laden.

Bush's critics contend those efforts have been hampered by a shifting of resources to the Iraq war.

With the six-year anniversary of the September 11, 2001, attacks approaching, Bush is eager to assure Karzai -- and the American public -- he is committed to shoring up Afghanistan and combating the Taliban and Al Qaeda.

But Karzai, who arrived at Camp David on Sunday, brought little encouraging news about the hunt for bin Laden, telling CNN's "Late Edition" the US and its allies were no closer than they were a few years ago to tracking down the elusive mastermind of the September 11 attacks.

"We are not closer, we are not further away from it. We are where we were a few years ago," Karzai said.

Bin Laden is believed by US intelligence officials to be hiding in the rugged tribal region of Pakistan, an area near the border of Afghanistan that has been a source of concern to Karzai because it is seen as a hotbed of Taliban activity.

US officials have underscored their support for Karzai, whose weak central government faces numerous challenges, including suicide bomb attacks by the Taliban, mounting civilian casualties and a burgeoning opium trade.

The Afghan president was treated at Camp David to a dinner of fried chicken and mashed potatoes, hosted by Bush and his wife, Laura. On Monday, the two leaders were to hold a news conference.

Despite his strong Western backing, Karzai has been the target of three assassination attempts and has struggled to build a robust central government amid longstanding tribal rifts and strong warlord control in the provinces.

The resurgence of the Taliban has led to the worst violence in Afghanistan since 2001, particularly over the last 18 months.

One issue Karzai wants to raise with Bush is his concern about a rise in deaths of civilians killed in airstrikes by US and Nato-led forces aiming at the Taliban.

And Bush may want to broach US concerns that Iran may be fueling violence by supplying weapons across the border.

However, Karzai disagreed that Iran was a source of problems, describing it instead as "a helper" to Afghanistan and a supporter in its quest for peace.

Bush and Karzai also will discuss the crisis involving 21 Korean hostages seized by the Taliban in July. The kidnappers have killed two of the 23 initially captured and are demanding the release of Taliban prisoners in exchange.

South Korea has appealed to the US and the Afghan officials to negotiate the release. Afghan officials are wary of making concessions for fear they might encourage more kidnappings.

"We are working very, very hard on this question," Karzai told CNN. "We will not do anything that will encourage hostage-taking, that will encourage terrorism. But we will do everything else to have them released."

White House National Security Council spokesman Gordon Johndroe said the United States urged the immediate release of the hostages and called the kidnapping an "an uncivilized and brutal act."  Reuters