With India blaming Pakistan-based elements for the Mumbai terror strikes, the US on Monday said Islamabad [Images] must "follow evidence wherever it leads" and lend "absolute" and "transparent" cooperation in the probe as US Secretary of State Condoleezza Rice [Images] headed for New Delhi [Images].

President George W Bush [Images] has asked Rice to travel to New Delhi on Wednesday amid apprehensions of tensions rising between India and Pakistan in the aftermath of Mumbai terror attacks [Images].

"President Bush has asked Secretary Rice to travel to India this week in the wake of the terror attacks that killed nearly 200 people, including six American citizens," a White House statement said.

"Secretary Rice's visit to India is a further demonstration of the United  States' commitment to stand in solidarity with the people of India as we all work together to hold these extremists accountable," it added.

Ahead of her visit to Delhi, Rice said the US shares "grief and anger" of Indian people and "what we are emphasising to the Pakistani government is the need to follow evidence wherever it leads and to do so in the most committed and firmest possible way."

Talking to reporters in London [Images], Rice said she did not want to jump to any conclusions on who is involved in the attacks "but this is time for a complete, absolute, total transparency and cooperation and that is what we expect (from Pakistan)."

She said it is "extremely important that there (should) be the highest levels of cooperation" between Pakistan and India at this point and "that means all institutions".

Bush has already talked to Prime Minister Manmohan Singh [Images] twice since the three-day attacks from November 26 and said the US will work together with the international community to bring the perpetrators of the terror act to book.

"President Bush told the prime minister that he has directed the state and defence departments along with other federal agencies to devote the necessary resources and personnel to this situation," White House spokesman Gordon Johndroe said as a team of FBI sleuths reached Mumbai.

Rice, who is cutting short her tour of Europe to travel to India, did not comment on reports that Pakistan-based Lashkar-e-Tayiba could have carried out the attacks.

External Affairs Minister Pranab Mukherjee has said that "elements" based in Pakistan were responsible for the deadly strikes and bluntly told Islamabad that it would affect the efforts to take the bilateral relations forward.

Rice talked about Pakistan President Asif Ali Zardari's [Images] pledge to improve ties with India and said "it's a difficult task for this new Pakistani government... They know this is a time to step up the task (of responding)."

On her visit to New Delhi, she said she had been asked by the US President "to express our absolute determination to help them (India) in any way that we can to help end this serious threat and bring those perpetrated this horrible tragedy to justice".

Rice has talked to Zardari after the Mumbai attacks.

There are fears in the US that with the perpetrators of Mumbai attacks originating from Pakistan, India could resort to military action against the western neighbour.