India and the United States on Monday inched closer to resolving their diplomatic stand-off on nuclear arms control but left further progress to a fourth round of talks in Washington in late August.

"We have more work ahead of us, which is why we are looking forward to more talks tomorrow and again late next month," U.S. Deputy Secretary of State Strobe Talbott told reporters as he emerged from a day of closed-door meetings in New Delhi.India's foreign ministry said the two sides, which have been fencing over the global non-proliferation regime since New Delhi conducted nuclear tests on May 11 and 13, had narrowed a perception gap in their "constructive discussions."

"There is forward movement and there is a narrowing of the gap in terms of each other's perception," a ministry spokesman said. "There is movement on both sides."

Since India's defiant nuclear step and tit-for-tat tests by arch-foe Pakistan, which sparked fears of a regional arms race, Washington has mediated in efforts to convince both countries to forsake further tests and deployment of nuclear arms.

India has already declared a unilateral moratorium on further nuclear testing. Pakistan has said it plans no more tests but could reconsider in national interests. Both have refused to sign the Comprehensive Test Ban Treaty (CTBT).

The seven-member team led by Talbott, the first senior U.S. official to visit New Delhi since the tests, included Assistant Secretary for South Asian Affairs Karl Inderfurth and Vice Chairman of Joint Chiefs of Staff General Joseph Ralston.

India's team was led by Jaswant Singh, a close aide of Prime Minister Atal Behari Vajpayee, with whom Talbott had already held separate talks in Washington and Frankfurt.