NEW DELHI - Ensuring justice in last November's Mumbai attack is a high priority for President Obama and the United States will keep pressing Pakistan for action against its planners, a top U.S. diplomat said on Wednesday.

The comments by Timothy Roemer, the new U.S. ambassador to India, are the strongest remarks from the United States in recent months as India complains of Pakistan's slow progress in punishing those behind the attack.

India blames Pakistan-based militants for the raid that killed 166 people and renewed tensions between the nuclear-armed South Asian rivals.

New Delhi said it was halting a 2004 peace process until Pakistan closed down terrorist networks on its soil.

The al-Qaeda, the Taliban, Lashkar-e-Taiba ... we have a common enemy with India. And we are pressing Pakistan hard on the Mumbai suspects, said Roemer, who served on the commission to investigate the September 11 attacks on the United States.

So this is a high priority for the president (Obama) and a high priority for the government to work with India on these efforts and to bring the perpetrators of this brutal attack, this blood-thirsty attack on Mumbai to justice.

FBI TESTIMONY

At the end of a nearly 60-hour siege on several Mumbai landmarks, Indian commandos shot dead nine of the 10 attackers.

The lone surviving gunman is facing trial in a Mumbai court which Wednesday recorded the testimony of a forensics expert from the U.S. Federal Bureau of Investigation (FBI).

The expert, whose name has been witheld, had examined five GPS units and one satellite phone -- at the request of the Mumbai police -- used by the attackers.

We retrieved the routes traveled from the GPS units on which Karachi and Mumbai were the stored locations, in addition to waypoints in between, the FBI official said.

India and Pakistan have shown signs of moving forward, opening an official level dialogue, partly pushed by Washington which wants the two countries to reduce tensions so that Islamabad can concentrate on fighting Islamist militants on its Afghan border.

But their formal peace process remains suspended.

Pakistan says it is committed to fighting terrorism and has arrested five people India blamed for the attack.

The list does not, however, include Hafiz Saeed, the founder of the militant group India has said was behind the attack, with Pakistan saying the evidence given by India failed to build a case for the arrest of Saeed.

Saeed was detained in the wake of the November attacks after a U.N. Security Council resolution put him on a list of people and organizations supporting al Qaeda.
But in June, a Pakistani court released him on grounds of insufficient evidence, prompting the Pakistan government to lodge an appeal with the Supreme Court for his re-arrest. The Supreme Court has adjourned the hearing without fixing a new date.

Asked if India's evidence against Saeed was credible, Roemer said he had told his government about the need to bring all the perpetrators of the Mumbai attack to justice.

Wherever they are I have communicated to my government several times ... that the people held in Pakistan for Mumbai attacks need to be brought to justice and that includes everybody that you mentioned, he said in reply to a question about the evidence on Saeed.

(Additional reporting by Rina Chandran in Mumbai; Editing by Alistair Scrutton and Bill Tarrant)