The U.N. Law of the Sea Treaty gets a new airing in the Senate this week, more than three years after it was stalled by conservative opposition and 13 years after it was submitted to the Senate by President Clinton.

The Foreign Relations Committee is to hear high officials of the State and Defense departments testify that it is in the United States’ interest to join 155 nations in ratifying the accord.

The treaty — formally the United Nations Convention on the Law of the Sea (Treaty Doc. 103-39) — was signed in 1982 and entered into force in 1994, when Clinton submitted it to the Senate.

After the committee voted unanimously to report the treaty to the full Senate in February 2004, critics denounced it at hearings of the Senate Environment and Public Works Committee, then led by Republican James M. Inhofe, R-Okla., and it never reached the Senate floor.

But Senate Majority Leader Harry Reid, D. Nev., hopes to bring it before the Senate this year, said spokesman Jim Manley.

The administration has long supported the accord and last May President Bush urged the Senate to act on it, in a statement warmly welcomed by Foreign Relations Chairman Joseph R. Biden Jr., D-Del., and ranking Republican Richard G. Lugar of Indiana.

“Joining will serve the national security interests of the United States, including the maritime mobility of our forces worldwide,” Bush said.

He said the pact would secure U.S. sovereign rights over extensive maritime areas and their valuable resources.

“Accession will promote U.S. interests in the environmental health of the oceans,” the statement said. “And it will give the United States a seat at the table when the rights that are vital to our interests are debated and interpreted.”

Since the 2004 Senate hearings on the treaty, global events have spotlighted the need to resolve competing claims on vital sea lanes and riches believed to lie beneath the ocean floor.

Russia last month symbolically staked its claim to the Arctic and its presumed vast energy resources when a Russian submarine planted a titanium flag on the seabed under the North Pole.

The melting of Arctic sea ice caused by global warming could bring to reality the long-sought Northwest Passage linking the Atlantic and Pacific oceans, sparking conflicting claims over territorial waters.

The treaty sets out detailed rules on the extent of territorial waters and includes seabed mining dispute resolution provisions. Thus developments in the Arctic are seen as giving new urgency to U.S. ratification.

“Unless the United States ratifies the treaty, Moscow will be able to press its claims without an American at the table,” Lugar said in an essay on the treaty last May.

He said that the treaty was now open to amendment and that “with America on the outside looking in,” the United States would have no say in decisions.

Opponents of the treaty say that it would infringe on U.S. sovereignty. Frank Gaffney Jr., president and CEO of the Center for Security Policy, expressed concerns at the 2004 Senate Environment hearing about the “supranational” International Seabed Authority created by the treaty.

“Environmental implications could be exacerbated by the ISA’s authority to apportion drilling and mining rights to other nations who may be less scrupulous than American companies in complying with environmental standards and practices this country holds dear,” Gaffney testified.

Treaty supporters say it provides crucial protection for the right of U.S. warships’ free passage through international “chokepoints.”

Lugar, who has long pushed for U.S. ratification, also cited what he said are important rights for oil and fishing industries and “natural resource provisions that are so thorough that the Law of the Sea has been called ‘the strongest comprehensive environmental treaty now in existence.’”

The treaty includes provisions on pollution and ocean dumping and calls for conservation of the oceans’ living resources.

In his essay, Lugar criticized “ideological posturing and flat-out misrepresentation by a handful of amateur admirals who have sought to cast a shadow over the treaty by suggesting that we are turning over our sovereignty to the United Nations.”

The criticisms, he said, “simply don’t hold water.”

The United States had initially opposed the treaty because of its provisions governing seabed mining but dropped its opposition after changes were negotiated.

George P. Shultz, secretary of state in the Reagan administration, in a letter to Lugar last June, expressed surprise that treaty opponents were invoking Reagan’s name in criticizing the treaty.

“During his administration, and with full clearance and support from President Reagan, we made it clear we would support ratification if our position on the seabed issue were accepted,” the letter said.

Treaty approval requires a two-thirds majority of the Senate — 67 votes if all senators are present and voting.

It is a high hurdle but one that supporters believe can be surmounted. “I think there will be a very strong vote for the treaty,” Lugar’s press secretary, Andy Fisher said last week.

Appearing at Thursday’s Foreign Relations hearing will be Deputy Secretary of State John D. Negroponte, Deputy Defense Secretary Gordon England and Admiral Patrick M. Walsh, vice chief of naval operations.

The committee plans an additional hearing next month featuring non-government witnesses.