The United States on Wednesday impressed upon India the need to take early next steps for implementation of the civil nuclear deal which has got caught in a political controversy.

US Ambassador to India David Mulford met Shyam Saran, the prime minister's special envoy on the nuclear issue, to discuss future of the atomic agreement.

Mulford, who was to leave for Washington hours later, wanted to assess the stance that the government would adopt in view of the Left parties' opposition to operationalisation of the deal, sources said.

The two deliberated on how to go about in implementing the agreement, with the US Ambassador emphasising the need for taking the next steps as early as possible as delay could endanger the agreement, they said.

Mulford will be in Washington tomorrow to brief the Bush Administration about the fate of the agreement. He is expected to apprise the administration about the measures India is taking to implement the deal.

After conclusion of the 123 Agreement, India is required to negotiate a safeguards agreement with IAEA and seek changes in NSG's guidelines to allow it to have nuclear trade with the international community.

Following these two steps, the 123 Agreement will be put to vote in the US Congress.

The meeting between Mulford and Saran assumes significance as it came a day after Mulford said India needed to take the last steps early to operationalise the deal as "time is of essence".

"Finally, the US Congress must vote once more on the 123 agreement, an action best accomplished by this Administration in the life of this Congress," Mulford said.

The US is keen that all the steps be taken during the tenure of Bush Administration, preferably by January next year when the process for Presidential elections will begin there.

Mulford's remarks came on a day when CPI-M asked the government to put a halt on operationalisation of the deal for six months, failing which the government would face a "political crisis".

The meeting came ahead of the special session of the Nuclear Suppliers Group on Thursday when the US would brief the 45-nation grouping on the agreement.

The Indo-US agreement needs approval of the NSG to allow international community to have nuclear trade with India.