By Qasim Nauman
ISLAMABAD (Reuters) - Pakistani political leaders hold all-party talks on Thursday to address growing American demands on Islamabad to tackle Islamic militants and the possibility that the United States might take unilateral military steps in the country.
Support is growing in Congress for expanding American military action in Pakistan beyond the drone strikes that already target militants in Pakistani territory, a senior Republican senator said.
The comments by Senator Lindsey Graham, an influential Republican voice on foreign policy and military affairs, follow remarks by the top U.S. military officer, Admiral Mike Mullen, accusing Pakistan last week of supporting the militant Haqqani network's September 13 attack on the U.S. embassy in Kabul.
Islamabad, which has received billions of dollars of U.S. aid despite its reluctance to go after the Haqqani network, faces the most intense pressure to tackle militancy since it joined the U.S. "war on terror" a decade ago.
Pakistan's military faced unprecedented public criticism after the United States' unilateral raid that killed al Qaeda leader Osama bin Laden in a Pakistani garrison town in May.
A similar U.S. operation against militant leaders in North Waziristan on the Afghan border, where American officials say the Haqqanis are based, would be another humiliation for the powerful military, which sets security and foreign policy.
Graham said in an interview with Reuters that U.S. lawmakers might support military options beyond drone strikes that have been going on for years inside Pakistani territory.
Those options may include using U.S. bomber planes within Pakistan. The South Carolina Republican said he did not advocate sending U.S. ground troops into Pakistan.
"I would say when it comes to defending American troops, you don't want to limit yourself," Graham said. "This is not a boots-on-the-ground engagement -- I'm not talking about that, but we have a lot of assets beyond drones."
Graham said U.S. lawmakers will think about stepping up the military pressure. "If people believe it's gotten to the point that that is the only way really to protect our interests, I think there would be a lot of support," he said.
Pakistan and the United States have been allies for decades. But their relationship is marred by mistrust. Pakistan, regarded as critical to U.S. efforts to stabilize Afghanistan, is often described as an unreliable partner.
Following U.S. accusations that some in the Pakistani government have aided anti-U.S. militants, Congress is re-evaluating its 2009 promise to triple non-military aid to Pakistan to a total of $7.5 billion over five years.
The non-military aid came on top of billions in security assistance Washington has provided since 2001, and is now rethinking as well.
Any unilateral U.S. military action would deepen anti-American sentiment which already runs high in Pakistan over drone strikes and other issues.
Many people question why thousands of Pakistani soldiers have died fighting what they believe is strictly America's war on militants since the September 11, 2001 attacks.
Pakistani politicians will have those sentiments in mind when they formulate a message for the United States in the all-party talks.
The head of Pakistan's military spy service, Lieutenant-general Ahmad Shuja Pasha, is expected to brief the meeting of politicians on recent high-level meetings with American officials over strained ties.
His comments are likely to indicate whether the security establishment, which was infuriated by allegations it is actively supporting the Haqqanis, will harden its stand or seek reconciliation with the Americans.
Army chief General Ashfaq Kayani, arguably the most powerful man in Pakistan, is expected to attend the talks.
The Haqqani network is allied with Afghanistan's Taliban and is believed to have close links to al Qaeda. It fights U.S. and NATO forces in eastern Afghanistan.
The group's leader says it is no longer based in North Waziristan and feels secure operating in Afghanistan after making battlefield gains.
Pakistan has vowed to help all sides create peace in Afghanistan. But it has come under fresh criticism from Afghan President Hamid Karzai, who has often questioned Islamabad's commitment to fighting militants.
After meeting with Afghanistan's political and religious elite to discuss the future of peace negotiations following the assassination last week of his government's top peace envoy, Karzai took a swipe at Pakistan.
"Pakistan did nothing to destroy terrorist strongholds, allowing them to train in its territory," Karzai was quoted as saying in a statement issued by his office.
"And now, if the Taliban is being used ... by the ISI, then Afghanistan has to talk with Pakistan and not the Taliban."
Many Afghans have long accused Pakistan and its main spy agency, the Directorate of Inter-Services Intelligence (ISI), of backing insurgent groups to further Islamabad's own interests. Pakistan denies this.
(Additional reporting by Zeeshan Haider in Islamabad, Mirwais Harooni in Kabul and Missy Ryan and Susan Cornwall in Washington; Writing by Michael Georgy; Editing by John Chalmers and Sanjeev Miglani)