US Secretary of State Condoleezza Rice pressed Congress to approve a nuclear deal with India after the agreement won the endorsement today from nations that supply nuclear material and technology.

"The main thing is that the international work is now done. I certainly hope we can get it through. It'd be a huge step for the US-India relationship," the top US diplomat told reporters as she travelled from Tunisia to Algeria during a trip to North Africa.

"It would be good to get everything finalised. I hope we can get it through Congress," Rice said.

But time is drawing near for US lawmakers to consider the deal. Congress has only a few weeks of work in September before it is scheduled to break for the rest of the year to campaign for November elections.

The Nuclear Suppliers Group, which governs the legal world trade in nuclear components and know-how, approved the deal after contentious talks and concessions to countries that feared the pact could set a dangerous precedent.

Some opposing countries, including Austria, Ireland, New Zealand, Norway and Switzerland, had expressed fears that a reversal of more than three decades of US policy toward India could set a dangerous precedent in the struggle to discourage other nations from pursuing weapons of mass destruction.

"This is an important step forward," Rice said after hearing of the approval by representatives meeting in Vienna.

"This is really a very good step forward for the nonproliferation framework. The India deal is landmark. It's no secret that India has been outside the nonproliferation regime for the entire history of its programme," she said.