US efforts to lift a 34-year-old embargo on nuclear trade with India were adjourned early Saturday after no headway was achieved on nuclear testing, a diplomat said.

US President George W. Bush and Secretary of State Condoleezza Rice both telephoned counterparts to put pressure on for a deal, diplomats said.

But after nearly 17 hours of negotiations, the Nuclear Suppliers Group meeting broke up with New Zealand, Austria and Ireland holding out against the deal, a diplomat said.

The talks had been meant to last only two days, but secretive 45-member group, which controls the international nuclear trade, said it would hold a third day of talks from 11:00am (0900 GMT) on Saturday.

NSG rules ban nuclear trading with India because it refuses to sign the Non-Proliferation Treaty, developed atomic bombs in secret and conducted its first nuclear test in 1974.

The United States wants a special waiver from NSG rules for India, so it can share civilian nuclear technology with India.

The United States argues the deal would bring India into the NPT fold and help combat global warming by allowing India to develop low-polluting nuclear energy.

Critics say the deal undermines international non-proliferation efforts and accuse the nuclear powers of pursuing commercial and political gains.

The main sticking point is possible nuclear testing by India, since New Delhi has not signed the Comprehensive Test Ban Treaty.

India has said it "remains committed to a voluntary, unilateral moratorium on nuclear testing."

But New Zealand, Ireland and Austria form a hard core of sceptics demanding a stronger commitment, a diplomat said.

"So far, the draft text (of the agreement) is weak, with no real condition or consequence should India test," the diplomat told AFP, speaking on condition of anonymity.

Initially, the Netherlands, Norway and Switzerland had also expressed reservations.

But following intense US pressure, these three have all supported the deal, while Austria, Ireland and New Zealand want further amendments.

Talks were being conducted at presidential and ministerial level, one diplomat said. Another said President Bush and Secretary of State Rice had both been on the phone to the countries concerned, so much so that there was talk of the countries feeling "bullied".

Speaking to reporters after the adjournment, acting US Undersecretary for Arms Control and International Security, John Rood, said he was "pleased with the significant progress that we've made throughout the day."

He said an Indian statement underlining its commitment to non-proliferation had "made a substantial impact on the governments of the Nuclear Suppliers Group and that sincerely facilitated the progress that we achieved today."

Rood said he felt "confident" an accord could be reached at the second meeting in two weeks to try to agree a change to its rules, which requires unanimous approval.

India issued a statement insisting it had "a long-standing and steadfast commitment to universal, non-discriminatory and total elimination of nuclear weapons."

"We remain committed to a voluntary, unilateral moratorium on nuclear testing. We do not subscribe to any arms race, including a nuclear arms race," the government statement said.

India had "an impeccable non-proliferation record," the statement said.

It "will not be the source of proliferation of sensitive technologies, including enrichment and reprocessing transfers. We stand for the strengthening of the non-proliferation regime," it added.

The International Atomic Energy Agency approved an India-specific safeguards agreement in August. The NSG represents the next obstacle before the deal can be finally approved by the US Congress.