Washington: The US-Pak military ties are at a ‘very difficult’ crossroads, the top American military commander has said, with the path to retrieve them not yet clear.

But Washington is nowhere close to severing its military ties with its longtime ally, Admiral Mike Mullen, Chairman of the US Joint Chiefs of Staff, told foreign journalists at a news conference here.

"We're in a very difficult time right now with respect to our military-to-military relationship," Mullen conceded in his last media interaction on Monday before he retires at the end of this month.

The retiring admiral said he hopes that the two nations would find a way to recalibrate those ties. "We need to work through the details of how this is going to happen."

Mullen was responding to questions about the fate of military ties to Islamabad in the wake of suspension by Obama administration of a USD 800 million military aid to Pakistan.

"I think that decision is representative of concerns, certainly, that are held in my Congress with respect to the status of the relationship, the needs to do certain things to move ahead here, and that's a very strong signal in that regard," he said.

Despite the recent visit here by Pakistan ISI chief Lt Gen Ahmed Shuja Pasha, media reports have said that strains continue in the military-to-military cooperation between the two nations.

But, the outgoing US military chief asserted that the two countries were not close to snapping the defence cooperation.

"I don't believe we're close to severing it, and we shouldn't do that. I think sustaining this relationship is critical. We've been through difficult times with them in the past, and we should see this difficult time through, in terms of sustaining this relationship over time," Mullen said.

He said his interactions with the military leadership of Pakistan, including General Ashfaq Pervez Kiyani, indicates that Islamabad too was supportive of continuing the bilateral relationship.