NEW YORK, OCT. 5 -- The United States and the Soviet Union worked out the remaining details of a new multilateral accord reducing conventional forces in Europe today but were unable to overcome obstacles blocking completion of a separate treaty on strategic nuclear arms, Secretary of State James A. Baker III said tonight.

Baker said after meeting with Soviet Foreign Minister Eduard Shevardnadze for six hours that he remained optimistic that a new strategic accord could be completed this year, as President Bush and Soviet President Mikhail Gorbachev pledged last December.

But neither he nor Shevardnadze were able to cite a major strategic arms dispute that was resolved by the talks, which took longer than planned. Shevardnadze said "we have . . . {made} some good progress on a number of complex issues," but he did not predict a treaty will be completed this year.

The officials said they had reached a final accord on combat aircraft, helicopters and geographic arms limitations under the treaty covering conventional, or non-nuclear, weapons deployed by 22 nations in Europe.

Shevardnadze said resolution of these details meant they could "indeed safely say" that the conventional arms accord will be signed at a Paris summit meeting of the 22 heads of state in November.

Shortly before their announcement, the two officials attended the unveiling of a new sculpture in front of the United Nations building that includes components of U.S. and Soviet medium-range ballistic missiles destroyed under a 1987 treaty. Referring to the crisis over Iraq's invasion of Kuwait, Baker said that he and Shevardnadze were eager to bury the Cold War "in the sands of Arabia" and called on Iraq to destroy its weapons of mass destruction.

Under the proposed strategic accord, U.S. and Soviet arsenals are expected to be reduced by 20 to 30 percent, leaving each side with 7,500 to 10,000 nuclear warheads capable of hitting each other's territory.