BEIJING (AFP) -- The nuclear deal between the United States and India received a generally positive response in the Asia Pacific, with Japan and Australia on Friday leading the upbeat assessments but China voicing caution.

U.S. President George W. Bush and Indian Prime Minister Manmohan Singh signed the deal in New Delhi on Thursday that paves the way for the lifting of three-decade-old restrictions on sharing civilian nuclear technology.

Bush and Singh hailed the deal as historic, with the arrangement being seen as a landmark moment in the improving bilateral ties following decades of strained relations that date back to the Cold War.

China voiced the strongest official note of regional caution shortly after the deal was announced when it said New Delhi and Washington must follow the rules of the nuclear non-proliferation regime.

"Cooperation must conform with the requirements and provisions of the international non-proliferation regime and the obligations undertaken by all countries," Foreign Ministry spokesman Qin Gang said on Thursday.

India and similarly nuclear-armed regional rival Pakistan have refused to sign on to the Nuclear Non-Proliferation Treaty (NPT).

However China, whose containment was believed to be one reason for the United States wanting to embrace India on the nuclear issue, publicly refrained from saying anything more critical.

Key regional U.S. ally Japan, which is also seeking closer relations with India, welcomed the deal.

"India is a country that shares the values of freedom, democracy, basic human rights and the rule of law with the United States and Japan," Chief Cabinet Secretary and government spokesman Shinzo Abe told reporters.

Australia welcomed the U.S.-India deal, saying Washington had at least convinced New Delhi to open up its civilian nuclear reactors to inspections from the UN's nuclear watchdog, the International Atomic Energy Agency.

"It's a good step forward in what's been a difficult situation," Foreign Minister Alexander Downer told public radio.

But Downer ruled out lifting a ban on uranium exports to India while New Delhi continued to refuse to sign the NPT.

Downer said Australia's policy on not exporting to countries that are not treaty signatories was clear and had not changed since the 1970s.

"It would open up questions of whether we'd export uranium to countries like Israel and Pakistan as well and I think it's probably easier for us to support the current policy," he said.

Australia, which has the largest uranium deposits in the world, is currently hammering out a deal with China to export the radioactive metal to the Asian giant.

However, Downer said the crucial difference was that Beijing had signed the NPT.

In Pakistan, where Bush was due to travel following his visit to India, officials expressed hope the United States would give Islamabad the same kind of civilian nuclear cooperation as it had just extended to New Delhi.

"We hope that we will also get the same kind of cooperation," Pakistani Foreign Ministry spokeswoman Tasnim Aslam told AFP on Thursday.

Meanwhile, IAEA Director General Mohamed ElBaradei said the U.S.-India deal would boost non-proliferation efforts.