The United States has said it was optimistic of overcoming obstacles blocking the final approval of the civilian nuclear cooperation plan with India.

'I am convinced that we are going to get to the mountaintop,' Undersecretary of State Nicholas Burns was quoted as saying while speaking to a conference on U.S.-Indian relations.

He said technical experts from the United States and India have concluded meetings in London on the nuclear issue. He said he will meet with the US delegation after their return and will confer afterward by phone with Indian Foreign Secretary Shiv Shankar Menon.

"It's going to require a little more hard work and some compromise," Burns said. "I'm confident that we can do that."

Burns also hinted that he might travel to India this week and seal the deal.

Indian officials also have expressed optimism about prospects for an agreement.