WASHINGTON, Sept 23: Militant safe havens in the Federally Administered Tribal Areas are threatening the existence of the civilian government in Islamabad and the region poses the greatest threat of terrorism against the United States, the US defence secretary said on Tuesday.

“The nature of the threat that they (the Pakistan government) face, beginning with the assassination of the current president’s wife and now most recently the attack on the Marriott hotel, makes very clear to the Pakistan government that they face an existential threat in the western part of their country,” Robert Gates told the Senate armed services committee.

About fresh deployments, the defence secretary said thousands of troops requested by commanders in Afghanistan were unlikely to be available until next spring at the earliest.

Gates said Islamabad’s new civilian government cannot publicly support US military action against militant targets on Pakistani soil and warned that any deterioration in Washington-Islamabad relations would hurt American interests.

“During this time of political turmoil in Pakistan, it is especially crucial that we maintain a strong and positive relationship with the government, since any deterioration would be a setback for both Pakistan and Afghanistan,” the US defence chief said.“The war on terror started in this region. It must end there.”

The rise in violence in Afghanistan had prompted President George Bush this month to announce a plan to deploy to Afghanistan a US Marine force of nearly 2,000 troops in November and an army brigade of around 4,000 troops in January.

US Army Gen David McKiernan, the head of the Nato-led force in Afghanistan, later said he needed three more brigades plus support units -- around 15,000 troops -- in addition to the deployments announced by Bush.

But Gates said a new deployment of that scale would be unlikely before next spring or summer due to troop commitments in Iraq, where about 150,000 US soldiers remain.

“Without changing deployment patterns, without changing length of tours, we do not have the forces to send three additional brigade combat teams to Afghanistan at this point,” Gates told the lawmakers.

“My view is that those forces will become available probably during the spring and summer of 2009.”

The United States now has about 33,000 troops in Afghanistan, including 13,000 under Nato command.—Reuters