In a move that could further complicate matters between the United States and Pakistan, Washington announced on Sunday that it would suspend a portion of its military aid to Islamabad, a major ally in the U.S. war in Afghanistan.

Relations between the two countries have been wobbly in recent months, since the U.S. raid on terror kingpin Osama bin Laden's compound in the country's north. The mission, which was conducted on Pakistani soil on May 2, was undertaken without the knowledge or consent of the Pakistani government, sparking complaints that the operation amounted to a breach of the Islamic republic's sovereignty.

Later, Pakistan's army decided to reduce the number of visas available to U.S. military trainers, a move that a senior U.S. military official said was the cause of this latest U.S. action.

White House Chief of Staff William Daley on Sunday told ABC's "This Week" program that 800 million U.S. dollars in military aid to Pakistan would be suspended, arguing that Pakistan's military has given cause to do so, although he did not specify. He added, however, that Pakistan has been an important ally in the U.S. fight against extremism.

Historically, Pakistan's mistrust for the U.S. has stemmed from its belief that it is fighting a U.S. war and that in the end Washington will abandon the country to fend for itself against radicals.

Lack of trust has been mutual, and U.S. officials have in the past questioned Pakistani leaders' commitment toward fighting terror groups and accused its military of only taking on terror groups that target Pakistan.

In this latest episode, it remains unknown whether U.S.-Pakistan relations will further deteriorate, remain the same, or whether this latest hurdle might already be blowing over.

Stephen Cohen, senior fellow at the Brookings Institution's Foreign Policy Studies Program, said that while it is difficult to envision things getting worse, such a scenario remains possible.

Lisa Curtis, senior research fellow at the Heritage Foundation's Asian Studies Center, said that by cutting U.S. military aid, the U.S. is signaling its willingness to risk a certain amount of deterioration in relations with Pakistan.

At the same time, Washington is leaving the door open for the possibility of better ties in the future and for eventually reinstating the aid if merited by Pakistani action. Even with the cuts, the U.S. is still providing large amounts of aid, and it is unlikely that the relationship would implode overnight, Curtis said.

"There is a great deal of room to recalibrate the relationship without allowing it to rupture," she said.

Nevertheless, the two countries could still be headed for worsening relations if the U.S. is not satisfied with the lack of concrete steps by Pakistan to help Washington stabilize Afghanistan and rein in terrorists that target U.S. interests, she said.

Michael Kugelman, associate at the Woodrow Wilson Center's Asia program, said the recent incident is merely the latest in a series of spats, and that in and of itself the funding cut is unlikely to fray ties to any great extent.

Moreover, Pakistan has a large and powerful army and sufficient supply of firepower, and having 800 million U.S. dollars withheld is no cause for concern, he said.

In an interview with the Voice of America on Monday, Pakistani military spokesman Major General Athar Abbas said the U.S. decision will not impact Pakistan's ability to continue operations again Islamic extremists.

Curtis, however, argued that the suspension of the coalition support funds -- about 300 million U.S. dollars -- could prompt the Pakistani military to curtail its operations in the tribal border areas and move more quickly to strike peace deals with various militants in the region.

That would ultimately have the impact of expanding the militant groups' influence at the expense of the state in those border areas. "Washington and Islamabad need each other to fight the terrorists in the tribal areas that threaten the security of both nations," she said.