"The FBI will pursue the evidence gathered there (in Mumbai) and they will eventually take the evidence to Pakistan because under our law, if Americans are killed, the US itself has a duty to pursue all avenues to the bottom of it," US Ambassador in Delhi David C Mulford told reporters in New Delhi.

"This is what the FBI is doing and will do in coming weeks and months," he said.

Noting that the US has been rallying behind India on the issue of November 26 Mumbai attacks, Mulford said Washington will pursue the investigation into the carnage to its ‘conclusion’.

"The FBI has been in Mumbai since early December and has, I must say, been welcomed there. The level of cooperation offered to the FBI is very very significant and very much appreciated by the United States," he said.

Asked about reports that Pakistan has rejected evidence given by the FBI, Mulford evaded a direct reply.

"I cannot comment on that because I don't think the process is anyway completed," he said.

Describing the cooperation offered by India to FBI as ‘very very positive experience’, he said some agency officials were still in Mumbai.

On whether FBI will be allowed into Pakistan to probe the Pakistani links into the attacks, Mulford said the American agency will be granted access to the country.

"The US has an FBI representative in Pakistan at the embassy there. So there is a person there and FBI people will certainly be granted access to Pakistan," he said.

Asked whether Pakistan was doing enough on the issue, he said, "The US will pursue this matter to its conclusion.

"The US will receive from the Indian Government what ever evidence there is. Because we have been involved in helping it gather evidence," he said.

Asked to clarify US position on whether it supports India's demand of handing over terrorists by Pakistan involved in the terror acts, Mulford said Washington has been supporting India on this issue as it is evident from the visits of Secretary of State Condoleezza Rice, Deputy Secretary of State John Negroponte and other senior military and intelligence officials.

"They have all made clear the support of the US. There can be no doubt at all on that," he added.

On reports of 'Jamaat-ud-Dawa', the front organization of terror outfit Lashkar-e-Taiba, that was banned by UN Security Council in the wake of the Mumbai terror attacks resurrecting under a new name, he only said "I cannot comment on that except that when names are changed, you know you don't change the spots on the leopard."

Asked to comment on India's handing over of evidence to Pakistan linking that country to the Mumbai attacks, he said "It's not possible for me to comment on an ongoing investigation."

Mulford said the investigations were taking "a great deal of time."