Ahead of a meeting between Prime Minister Manmohan Singh and US President Barack Obama in London, India on Monday said it "won't stand in the way" of Comprehensive Test Ban Treaty (CTBT) provided it "actively contributes to nuclear disarmament".
"We won't stand in the way... but it should be a CTBT which actively contributes to nuclear disarmament," Foreign Secretary Shivshankar Menon told reporters in New Delhi when asked about India's position on the signing of the CTBT - a key non-proliferation priority of the Obama administration.
"We are not sure if the CTBT in its present form addresses our concerns," Menon said. "Our position remains the same and has been consistent."
Manmohan Singh will meet Obama in London on the sidelines of the G20 summit in Thursday. The CTBT issue may figure in the discussions between the two leaders.
India has refused to sign the CTBT on grounds that it tends to create a nuclear apartheid by dividing the world into nuclear weapon states and non-nuclear weapon states.
Last week, India's former foreign secretary Shyam Saran, also prime minister's special envoy on climate change and nuclear issues, asserted that New Delhi will not sign the CTBT unless the world moves "categorically towards nuclear disarmament in a credible time-frame".
Saran acknowledged that the CTBT is "an issue that has been seen as potentially a contentious one in our relations with the new US administration".
"India has been a consistent votary of a CTBT but did not sign the CTBT as it eventually emerged because it was not explicitly linked to the goal of nuclear disarmament," Saran said at The Brookings Institution, a Washington think tank.
But if "the world moves categorically towards nuclear disarmament in a credible time-frame, the Indo-US differences over the CTBT would probably recede into the background", Saran said.