Pakistan-US relations have been strained since navy seals killed Osama bin Laden in a raid on May 2 [GALLO/GETTY]

The Pakistani and United States' military and spy agency officials have held a flurry of meetings as part of an effort to keep their relationship going.

Ahmed Shuja Pasha, the head of Inter-Services Intelligence [ISI], Pakistan's spy agency, met acting CIA director Michael Morell in Washington on Thursday, while the generals leading the US mission in Afghanistan met top military officials in Pakistan.

Pasha's visit comes just days after the US suspended $800m of military aid to Pakistan, allegedly over non-co-operation of this South Asian country in the fight against al-Qaeda and Taliban.

Nonetheless, both countries are intent on maintaining the dialogue, as they rely on each other.

Pakistan needs the US for financial assistance, both military and humanitarian, while the US needs a strong relationship with Pakistan for help in its mission in Afghanistan.

Few details were available about the meetings, but US embassy said those gathered "discussed various topics of mutual interest and ways to improve regional security".

A Pakistani official said prior to the talks that Islamabad was backing away from demands that US military personnel vacate Shamsi Air Base, in Baluchistan province, used for launching drone attacks.

The US has launched armed drones and observation craft from there to keep the pressure on Taliban and al-Qaida in Pakistan's tribal areas, but Pakistan government barred US from using the base under growing public anger.

The official said they are satisfied for now with a US agreement to launch drone strikes in Pakistan from US bases in neighbouring Afghanistan, and restricting the use of Shamsi only for drones that need to land because of bad weather.

The US and Pakistan are old allies, but their relationship has been strained since US commandos killed al-Qaeda leader Osama bin Laden in a raid about 60kms from the capital city of Islamabad.