Joint Chiefs of Staff Chairman Mike Mullen and his Pakistani counterpart General Ashfaq Kayani sat down for more than two hours of talks late Friday on the sidelines of a NATO conference in Seville, Mullen's spokesman Captain John Kirby told AFP Saturday.

"They agreed that the relationship between our two countries remained vital to the region and that both sides had taken positive steps to improve that relationship over the past few months," Kirby said.

"They also discussed the state of military-to-military cooperation and pledged to continue to find ways to make it better."

During his meeting with his Pakistani counterpart, Mullen expressed "deep concerns about the increasing -- and increasingly brazen -- activities of the Haqqani network and restated his strong desire to see the Pakistani military take action against them," said Kirby.

While relations are frayed, Pakistan is seen as key for US military operations in Afghanistan, where the United States is to trying to beat down a resilient Taliban insurgency.

Copyright AFP (Agence France-Presse), 2011