The United States has warned that its new Afghan strategy could fail unless Pakistan intensifies its fight against the militants.

US President Barack Obama has called on his Pakistani counterpart Asif-Ali Zardari to broaden his battle against the militants, The New York Times reports on Monday.

Obama has also offered a range of new incentives to the Pakistanis in exchange for their cooperation.

The incentives include enhanced intelligence sharing and military cooperation. The report indicates that the offer has been made to Pakistanis through a letter that was carried by Obama's national security adviser, General James Jones.

Obama is to announce his much-awaited strategy for Afghanistan in the coming weeks. The new war plan is expected to include the deployment of up to 40,000 more US troops to the war-ravaged country.

Washington has placed Pakistan at the forefront of its so-called war against al-Qaeda and has been increasingly concerned by the growing insecurity in a country where more than 2,500 people have been killed in violence related incidents in the past 28 months.

RZS/MB