“We cannot tolerate a world where innocents are killed by extremists based on twisted ideologies,” Obama, who takes office on January 20, told reporters in Chicago after naming his national security team. “We’re going to have to bring the full force of our power — not only military but also diplomatic, economic and political — to deal with those threats. Not only to keep America safe but also to ensure that peace and prosperity continue around the world.”

Obama pointed to South Asia as the area of greatest concern. “The situation in Afghanistan has been worsening. The situation in South Asia as a whole and the safe havens for terrorists that have been established there, represent the single most important threat against the American people,” he said.

He said while sovereign nations obviously have the right to defend themselves, he did not want to comment on the specifics surrounding the Mumbai attack. “I am confident that India’s great democracy is more resilient than killers who would tear it down,” he said. “I can tell you that my administration will remain steadfast in support of India’s efforts to catch the perpetrators of this terrible act and bring them to justice. And I expect that the world community will feel the same way.”

Secretary of State Condoleezza Rice, who is reaching New Delhi on Wednesday to try and lower tension between India and Pakistan, said the US made clear to Pakistan President Asif Ali Zardari that “this is a time for complete, absolute, total transparency and cooperation and that is what we expect (from Pakistan)” in the investigation into the Mumbai attacks that killed nearly 200 people, including six Americans.

“What we are emphasising to the Pakistani government is the need to follow the evidence wherever it leads and to do that in the most committed and firmest possible way,” she told reporters travelling with her to London, where she will discuss India-Pakistan tensions with Britain’s foreign minister.

Rice said while bodies were still being identified in Mumbai, she believed all known Americans were accounted for. “We share the grief and the anger of the Indian people. Americans were also killed in this attack and they were killed deliberately because they were Americans. That makes this of special interest and concern... to the United States,” she said.

She said there needed to be the highest levels of cooperation by law enforcement and intelligence agencies from both countries, a view later underlined by Britain’s Foreign Secretary David Miliband at a news conference with Rice. “It is precisely at this moment of strain... that we need very strong statesmanship and leadership to assert that it is joint action, and cooperative action, that will make the difference between stability and instability,” Miliband said.

Rice will drop at least two stops — Rome and Helsinki — from a European tour this week and visit New Delhi instead. Asked whether she was concerned these latest tensions could lead to a full-blown conflict, Rice played down the risk. But she conceded a difficult task lay ahead for the new civilian government in Pakistan, which has threatened to move troops from its western border with Afghanistan to the Indian frontier if tensions escalate.

“This terrorism threat has been very deep and growing for a long time. We have made a lot of progress against these organizations but yes, I do think that this is an element that bears watching and that gives us... more reason to make sure that we get to the bottom of it and as quickly as possible.”