Washington, Sep 7 (PTI) : The US has sought more progress in the trial of 2008 Mumbai terror attacks being held in Pakistan and said it wants to see "accountability and justice" for the 166 people, including six Americans, killed in the incident.

"We've been very clear that we want to see accountability and justice in the case," State Department Deputy Spokesman Mark Toner told reporters yesterday.

"There were American citizens who lost their lives in those terrible attacks. We've long encouraged and pushed for greater counter-terrorism cooperation, and that includes the sharing of intelligence between India and Pakistan in that regard," Toner said in response to a question.

"We're making our concerns clear that they need to go after all the terrorist groups that are operating or seeking (safe) haven on their soil. And that's been our clear objective for a long time now. We've seen progress but we need to see more," he added.

The trial has been underway in Pakistan for more than six years. The mastermind of the attacks, Lashkar-e-Taiba operations commander Zaki-ur Rehman Lakhvi, lives at an undisclosed location after getting released from jail on bail over a year ago. The other six suspects are in Adiala Jail in Rawalpindi.

The court proceedings have come to a halt as India is yet to send 24 witnesses in the case to Pakistan to record their statements in the trial court. Pakistan says the trial cannot be concluded unless India sends the witnesses.

As many as 166 people were killed and more than 250 injured in the attack carried out by 10 LeT terrorists. Nine assailants were killed while the lone survivor, Ajmal Kasab, was captured and later executed.