Islamabad, Sep 15 (IANS) Pakistani Army chief Gen. Ashfaq Parvez Kayani and chairman of the US Joint Chiefs of Staff Admiral Mike Mullen will meet in Spain on the sidelines of a NATO conference, "an indicator that things are improving", an official said.

The two officers will be in Seville for NATO's Chiefs of Defence annual conference Sep 16-17, Dawn reported.

Captain John Kirby, spokesman for the US joint chiefs of staff, confirmed that the two "would be having a conversation in Spain".

Ties between the two countries soured in the aftermath of the commando raid on the Osama bin Laden compound in Abbotabad in which the Al Qaeda leader was killed.

A source told Dawn the highlight would be formalisation of a deal on the return of US military trainers who were expelled from Pakistan as a fallout of the raid.

The number of trainers was initially cut from 130 to 39 and subsequently to four. Even the strength of the media section of the US Office of Defence Representative in Pakistan was slashed. In retaliation, the US partially suspended military aid for Pakistan, the daily said.

The NATO conference will discuss progress of transition in Afghanistan and NATO involvement in the country after the coalition forces' withdrawal in 2014.