He described Indian team's victory as a "historic" and "spectacular" feat.
Roemer congratulated Tendulkar for realising his wish of winning the World Cup for his country.
"We want to congratulate the magnificient decision-making of the Indian captain Dhoni, who was flawless in exercising great judgement," the envoy said here after meeting Foreign Secretary Nirupama Rao.
Roemer said he himself wanted to visit the India Gate here to witness the mass celebrations over the Indian victory but was advised against it by his security staff in view of the traffic jams there.
Asked about cricket diplomacy between India and Pakistan, he said, "it looks like it had attraction, it had a very optimistic start."
Hailing the leaders of India and Pakistan for dialogue between the Home Secretaries and "more talks" scheduled to take place in April, Roemer said, "You have three things working at once in these talks. You have cricket diplomacy, you have the real substance and engagement on issues, which is critical and then you have the people-to-people ties. That is something which the US applauds."
He, however, added that the US "recognises that only India and Pakistan will determine the pace" of dialogue.
The US Ambassador also praised the Indian security forces and police for having "worked hard and tirelessly" to successfully conduct the event.