Allied forces in Afghanistan have made "hopeful gains" over the past eight years, U.S. President George W. Bush said Monday in a surprise final visit to the country before he steps down in January.

U.S. President George W. Bush walks with Afghan President Hamid Karzai on arrival at the presidential palace in Kabul on Monday. (Musadeq Sadeq/Pool/Associated Press)

Greeted by about 1,000 U.S. and other troops at a pre-dawn rally at Bagram Air Base, Bush received loud cheers of support as he walked into the hangar.

"Afghanistan is a dramatically different country than it was eight years ago," he told the crowd.

"We are making hopeful gains."

At a time of deteriorating security in many parts of the country, Bush said the increasing attacks across Afghanistan were proof that a growing number of NATO troops are battling with insurgents in an effort to drive them out.

He then travelled to the capital, Kabul, by helicopter to meet with Afghan President Hamid Karzai.

"I and the Afghan people are very proud and honoured to the profoundest depth of our hearts to have President Bush with us here today," Karzai said as the two leaders sat side by side in the Afghan presidential palace.

Karzai also lamented that it took 2½ years and repeated requests to spur Bush's second visit to Afghanistan, where more than 30,000 U.S. troops are stationed.

The Afghan president added that he wished the U.S. president had more time so the Afghan people could see Bush in person.

At the end of the meeting, Bush thanked Karzai before telling him: "You can count on the United States. Just like you've been able to count on this administration, you'll be able to count on the next administration as well," referring to U.S. president-elect Barack Obama and his team.

Obama has called the situation in Afghanistan an "urgent crisis," and said he hopes to shift troops from Iraq and bolster the U.S. presence in Afghanistan. Commanders there want at least 20,000 more forces, but cannot get them unless some leave Iraq.

American troops have been in Afghanistan since 2001, when the Sept. 11 attacks in the United States led America to invade with an international coalition and oust the hard-line Taliban regime that had supported al-Qaeda.

Conflict increasing

Bush's visit comes at a time when military violence is at its highest level since the invasion, with a growing U.S. and allied death toll, and when the political situation for Karzai is increasingly complicated.

Bush's visit to Afghanistan was made amid even greater security than his surprise weekend visit to Iraq, the CBC's David Common reported from Kandahar. The president arrived at Bagram in his private jet, Air Force One, with the lights out and before the sun came up.

In this video image, a man throws a shoe at U.S. President George W. Bush during a news conference with Iraq Prime Minister Nouri al-Maliki on Sunday (Associated Press) Reporters accompanying him were barred from telling even their family members about the Afghanistan trip, Common said.

Bush's handlers were said to be especially edgy after an Iraqi reporter threw his shoes at Bush during a news conference in Baghdad on Sunday, which is a particular sign of disrespect in some Arab nations.

The man, identified as Muntadar al-Zeidi, was dragged away yelling, "This is your farewell kiss, you dog!"

The reporter was being held for questioning Monday by the Iraqi prime minister's guards over whether anybody paid him to hurl his footwear at Bush, and was being tested for alcohol and drugs, said an official, speaking on condition of anonymity because he was not authorized to talk to the media.

Thousands of Iraqis protested al-Zeidi's detention Monday, lauding the reporter as a national hero.

Bush was welcomed to Iraq, however, with a formal arrival ceremony, which was not part of his previous three trips.

The trips to Iraq and Afghanistan marked Bush's last visit to either war zone before Obama takes office Jan. 20, and followed recent trips made by U.S. Defence Secretary Robert Gates to both countries.

40 militants reportedly killed

Speaking in Afghanistan on Thursday before a meeting with Gen. David McKiernan, the commander of U.S. and NATO forces there, Gates said the U.S. military will deploy thousands of additional troops into Afghanistan by next summer.

He will be the only member of the Bush administration to retain his post under Obama.

Gates has said the surge in U.S. troops is particularly important ahead of next fall's national elections. Karzai has said he intends to run again, and the Taliban is expected to try to disrupt the vote.

Meanwhile, there were reports Monday that 40 militants have been killed in a joint Afghan-NATO operation in southern Afghanistan, including a Taliban commander in the region.

The bodies of seven insurgents have been recovered following the operation in Helmand province in the districts of Nad Ali and Murja, according to a spokesman for the provincial governor. Intelligence sources have informed the government that another 33 fighters were also killed, he said.

Lt.-Cmdr. James Gater, a spokesman for NATO's International Security Assistance Force, confirmed that a joint operation in Helmand has been underway since Thursday, but would not provide casualty figures.

With files from the Associated Press