Pakistani leaders jousted Wednesday over a multibillion-dollar U.S. humanitarian aid bill that the ruling party praises as a lynchpin to strengthening democracy here but that opponents say will lead to greater American interference in Pakistani affairs.

The bill, which awaits President Barack Obama's signature, would give Pakistan $1.5 billion annually over the next five years for democratic, economic and social development programs. It also allows "such sums as are necessary" for military aid.

The U.S. says the bill is aimed at alleviating poverty here and lessening the allure of Islamist militant groups in a country seen as crucial to the American fight against the Taliban and al-Qaida in neighboring Afghanistan.

Opposition leaders planned to air their concerns about the aid package in Parliament later Wednesday, but political officials issued statements about it throughout the day.

Critics complain the bill could authorize the U.S. to broaden airstrikes in the country and interfere in Pakistan's nuclear program.

"The tone and tenor of the bill in terms of conditionalities is not just intrusive, it's also overbearing and bordering on the humiliation of Pakistan," said Mushahid Hussain, a leader of the Pakistan Muslim League-Q. "We are not being treated kindly."

The dispute highlighted Pakistani angst about America's growing presence in the country. The criticism seems unlikely to derail the aid program, but it has stung the pro-Western Pakistani government, which has directed ruling party members to defend the aid package.

The bill "has been greatly misunderstood in Pakistan by some sectors, and I also believe that certain opposition groups have deliberately misquoted and distorted the facts of the bill to achieve certain political ends," said Farahnaz Ispahani, a top aide to President Asif Ali Zardari.

The debate comes as the army steps up preparations for a new offensive against militants in the South Waziristan tribal region, in what could be one of the most important operations against militants in Pakistan since 2001. South Waziristan is considered al-Qaida and the Taliban's major stronghold in the lawless northwest region bordering Afghanistan.

Maj. Gen. Athar Abbas, the army's chief spokesman, did not give a start date for the offensive but the way he referred to the operation suggested a decision had been made to launch one.

"God willing, peace will again be restored in the area through a successful operation," he told the ARY news channel.

Abbas did not say what kind of operation may be in the works — a limited one relying mostly on air power or a fully fledged offensive with thousands of ground troops aimed at clearing, then holding the whole region. The army abandoned early offensives and signed peace deals with militants in Waziristan after they put up a fierce fight.

Moving forcefully into South Waziristan is likely to gain praise from the United States. U.S. officials have long pressed Pakistan to eliminate safe havens on its soil used by militants to plan attacks in Afghanistan.

An operation in South Waziristan will face steep challenges, ranging from harsh terrain to well dug-in militants.

Pakistan's military said months ago it was planning an operation aimed at eliminating Baitullah Mehsud, the Pakistani Taliban chief, in South Waziristan. But the U.S. killed Mehsud in a missile strike in August, and since then, there have been lingering questions over whether Pakistan would try to dismantle the rest of his network there.

Analysts say 10,000 well-armed militants, including foreign fighters, are in the region.

Abbas said the army had already tried to weaken the militants by surrounding them, blocking roads and targeting them through air strikes. The point was to weaken the militants before a full-scale offensive.

"As we all know, this group and this organization has fighters and they will offer a tough resistance in this area," Abbas said.

The United States and other Western nations have been heartened by the army's recent offensive against the Taliban in the Swat Valley, but questions remain over the country's overall commitment to the fight against militants it once nurtured for proxy wars in India and Afghanistan.