A NATO political assembly tonight called for early Senate ratification of the U.S.-Soviet strategic arms limitation treaty, in a resolution seen as an important victory for supporters of SALT II.

The North Atlantic Treaty Organization members also came out in favor of the deployment of new U.S. intermediate-range nuclear arms in Western Europe. It said, however, that such deployment could be scrapped if the Soviet Union is prepared to negotiate a reduction of its nuclear missiles aimed at Western Europe.

The outcome of today's voting is viewed by many observers as an important boost for the Carter amdinistration, which has placed its prestige behind both SALT II ratification and the deployment of intermediate-range missiles in Western Europe.

The SALT resolution was adopted unanimously after Sen. Henry Jackson (D-Wash.), a leading opponent of the treaty, warned the assembly against setting "a dangerous precedent of dictating how the Senate shall vote."

The North Atlantic Assembly is nominally independent of NATO but serves as an unofficial link between the alliance and legislators of member states. The assembly meets each fall and encourages political discussion of NATO affairs.

There were 38 abstentions on tonight's SALT resolution, including the U.S. delegation. The delegation, including 11 senators, decided not to take a stand on the issue after two private sessions that several senators described as "very rough" and "exceptionally acrimonious."

Sens. Orrin Hatch (R-Utah) and Ernest Hollings (D-S.C.) charged that the proceedings had been "rigged." Hatch said supporters of SALT II had met secretly with President Carter and his counselor, Lloyd Cutler, last week to plan what Hatch called today's "manipulation of the assembly."

Supporters of SALT II, led by Sens. Joseph Biden (D-Del.) and Jacob Javits (R-N.Y.), hailed the assembly's "strong expression of support" as an important element in the ratification fight.

"This could very well be decisive on the ratification vote," said Sen. Donald Riegle (D-Mich.) said.

After four days of negotiations, today's resolutions reflected the mood of the West Europeans, who insist that ratification of SALT II is necessary to persuade public opinion in their countries to accept new American nuclear weapons.

U.S. Senate differences over SALT II, as well as the linkage between its ratification and deployment of new U.S. nuclear weapons in Europe, gave special importance to the 25th annual session of the North Atlantic assembly. Normally such gatherings are discussion sessions by Western political leaders, who are rarely called upon to vote and take a direct role on a key issue of common interest.

SALT's supporters got an unexpected boost from Prime Minister Joe Clark of Canada, who told the assembly this morning that Canada "fully supports this agreement as a valuable contribution to stability in strategic weapons." Clark said "a third round of SALT" should deal with the intermediate-range missiles in the European theater.

Clark also said that Soviet President Leonid Brezhnev's arms proposal in his Oct. 6 East Berlin speech "is to be welcomed and indeed applauded." He said Brezhnev's plans "require analysis and clarification."

The Soviet leader pledged to reduce unilaterally Soviet conventional forces in East Germany and curb Moscow's medium-range nuclear missiles in the European theater if the Western allies agreed not to place equivalent U.S. missiles on the continent.

The assembly's resolution on NATO's military modernization plans for the next decade also "welcomes Soviet readiness to negotiate" curbs on intermediate-range missiles, but it said that Brezhnev's Oct. 6 speech was "not yet a sufficient basis for negotiation."

Today's vote appears to clear the way for adoption by NATO at its December meeting of a U.S.-proposed modernization program that would include deploying Pershing 2 and Tomahawk cruise missiles in Europe.

But the assembly left a way open to include intermediate-range nuclear weapons in Europe in SALT III negotiations by saying modernization should be implemented "in a way that concrete results of arms control negotiations with the Soviet Union can be taken into account at any time during the period between" December and 1983, the earliest possible deployment of the new system.

If the Soviet Union is prepared to "reduce its own long-range" forces, the NATO assembly recommended that the new nuclear weapons could be renounced by NATO countries.

Taking account of West German sensitivity that it not be the only European member with nuclear weapons on its soil, the assembly urged that NATO provide for deployment "in several alliance member states, not just one European country."