Afghanistan needs more than extra international troops to combat extremism, President Hamid Karzai said here Tuesday, as US President George W. Bush announced reinforcements.

Karzai said an increase in troops was welcome as long as they were "effectively fighting against terrorism and effectively addressing the question of the sanctuaries" -- a reference to suspected rebel bases in Pakistan.

But "in the long term and as the only solution, it is the building of the Afghan state institutions that matters," he said, addressing a joint press conference in Islamabad with Pakistan's new president, Asif Ali Zardari.

This included Afghanistan being able to "defend its territory and provide safety and for the people on its own," he told reporters.

Bush announced Tuesday about 4,500 extra troops for Afghanistan from November with an accompanying drawdown of about 8,000 in Iraq.

"Afghanistan's success is critical to the security of America and our partners in the free world. And for all the good work we have done in that country, it is clear we must do even more," he said in Washington.

There are almost 70,000 foreign troops in Afghanistan, most of them with a NATO-led International Security Assistance Force (ISAF) and some with a separate US-led coalition.

Rather than more foreign soldiers, "the Afghan defence ministry emphasises more focus and investment on the Afghan army and Afghan forces which is a better solution in the long term," spokesman Mohammad Zahir Azimi said in Kabul.

International soldiers, mainly from the United States, are assisting in the training and equipping of the Afghan military, which was destroyed during the civil war of the early 1990s.

The army now numbers about 70,000 soldiers and is envisaged to almost double in size.

The head of the Afghan parliament's defence commission, ex-general Noorulhaq Olumi, said there were enough foreign soldiers and called instead for more emphasis on drawing in disaffected Afghans and focusing on Pakistan.

"We must diagnose the roots of the problems and cure them and not only resort to cannons, tanks and fighter planes and calling everybody 'enemies'," he said.

"A healthy government needs to be formed, the rule of law needs to be enforced to avoid swelling the group of people exhausted by corruption, insecurity and injustice and adding to the opposition," he said.

ISAF commanders have long been called for extra soldiers and equipment to be sent to Afghanistan, where deployments in the south are in particular under pressure from Taliban-led insurgents.

ISAF spokesman Brigadier General Richard Blanchette said more soldiers would enable the military to do more to tackle insurgents but also to train the Afghan National Army (ANA).

"We can do more when we have more troops but our real aim is to help the Afghans produce troops of their own and to be able to train enough ANA, we need to have more manpower," he told AFP.