Secretary of State Condoleezza Rice called on Congress Wednesday to approve an unprecedented U.S. plan to share nuclear technology with India, saying the deal will not trigger an arms race in Asia.

Her testimony was received cautiously. Senate Foreign Relations Committee Chairman Richard Lugar agreed that India under the deal would submit to more international safeguards.

But the senator, an Indiana Republican with a strong interest in arms control, said the agreement "would not prevent India from expanding its nuclear arsenal."

And Sen. Joseph Biden, D-Del., said "it comes down to a simple bet we are making, that India appreciates as much as we that the two nations have the potential to be anchors for stability."

Biden, the senior Democrat on the committee, said he would probably vote for the accord.

And, taking a tough line, Sen. Paul Sarbanes, D-Md., said the administration was asking Congress to approve the agreement without divulging the safeguards. They will be given to the International Atomic Energy Agency, but Sarbanes said, "I don't know they should be substituted for Congress."

But Sen. George Allen, R-Va., said "this is a good bet," when benefits to Indiaand the rest of the world are taken into account. The two countries share democratic values and there is a shared sense of security, he said.

At the committee hearing, Rice addressed critics who say the plan President Bush agreed to last month with India could dramatically increase India's nuclear arsenal and weaken efforts to prevent the spread of nuclear weapons.

"Civil nuclear cooperation with India will not lead to an arms race in South Asia," she said.

India has never signed the Nuclear Non-Proliferation Treaty and, Rice said, is unlikely ever to do so.

"We are simply seeking to address an untenable situation," she said. "This agreement does bring India into the nonproliferation framework, and does strengthen the regime."

Rice said the "path-breaking" deal "obviously deserves the support of the U.S. Senate." The pact, which must be approved by Congress, strengthens U.S. ties with the world's largest democracy but also upends more than three decades of U.S. law and policy.

Rice also was scheduled to appear later before the House International Relations Committee.

Her appearance comes at a time of growing domestic disenchantment with U.S. foreign policy. Uncertainty over the military course of a rising China, unceasing turmoil in Iraq and stalemated Mideast and nuclear diplomacy over Iran and North Korea pose difficulties for Rice, even though her own performance continues to receive rave reviews on Capitol Hill.

The election season is dawning for members of Congress and those who aspire to replace them. They all are aware of public discontent with the Bush administration's global record on several fronts.

The new U.S. strategic partnership between Washington and New Delhi reverses restrictions on trade with states, such as India, that did not accept comprehensive international safeguards over all their nuclear facilities. The administration's response is that the deal will foster nonproliferation by conditioning India's purchase of foreign-made nuclear reactors on opening its civilian facilities to international inspections.

However, the Congressional Research Service, in a report last week, noted that India would have the sole right to decide which reactors are civilian and which are military, which need not be under international supervision.

Undersecretary of State Nicholas Burns, who played a pivotal role in negotiating the agreement, has offered assurances that "India can be trusted."

But Sen. Barbara Boxer, D-Calif., a member of the Foreign Relations Committee, is critical of the agreement.

"I do not share the view that closer U.S.-India ties will be a counterweight to China, which seems to be the unstated yet driving force behind this deal," Boxer said in remarks prepared for delivery at the hearing. "This type of thinking is not only outdated and dangerous, it flies in the face of reality."

Boxer said India's recent record indicates that it has no interest in being a "hedge" against China. "It is naive to think otherwise," Boxer said.

In advance of the hearings, Rep. Tom Lantos, D-Calif., a supporter of the deal, said Rice's testimony would put the nuclear cooperation issue "front and center for the first time."

The House committee's senior Democrat, Lantos described as "jarring" the disclosure this week that two Iranian ships have visited ports in India.

The State Department said the visits do not suggest India was training or contributing to Iran's military capabilities.