A U.S. official praised Soviet leader Mikhail Gorba-chev for overcoming resistance from Warsaw Pact nations to a landmark agreement on human rights that also paves the way for a new round of arms-reduction talks.

Secretary of State George Shultz arrived Monday for ceremonies marking the formal endorsement of the agreement by the 35-nation Conference on Security and Cooperation in Europe. He was expected to address the conference Tuesday in his last mission abroad as America's top diplomat.The 26-month conference ended with approval of the document strengthening human-rights safeguards, providing for greater East-West cooperation and giving a mandate to new European disarmament talks in Vienna this spring involving the 23 NATO and Warsaw Pact countries.

In Brussels, NATO Secretary-General Manfred Woerner said the agreement offered the prospect of substantial improvements in the security and stability of Europe.

"NATO welcomes the successful conclusion of the mandate for negotiations on conventional armed forces in Europe . . . ," Woerner said in a statement issued by NATO. "These achievements demonstrate that allied initiatives and determination have paid off.

Woerner said he also was pleased that "this progress in the security field is accompanied by significant advances in the area of human rights and humanitarian concerns."

But sources said Romania was balking at the wide-ranging document signed Sunday by representatives of NATO, the Warsaw Pact and 12 other European countries.

Although signatories to the document pledged adherence to strict guidelines on human rights, but Romania said it would apply its own interpretation to the agreement.

The pact is not legally binding but is a declaration of intent to carry out far-reaching provisions involving economic, scientific and technological cooperation, military security and human rights, officials said.

Especially significant is a measure giving countries the right to ask any other country to account for specific cases in which the rights of individuals appear to have been violated.

The conference, held in Vienna since November 1986, also agreed to a series of follow-up meetings in areas ranging from human rights and access to information to environmental protection.

The document was expected to be formally endorsed by the foreign ministers of the United States, Canada and 14 other NATO nations, seven Warsaw Pact states and 12 other nations in Europe during a three-day ceremony beginning Tuesday.

Secretary of State George Shultz, making his last official trip abroad, was scheduled to address the conference Tuesday.

The chief U.S. delegate to the conference, Warren Zimmermann, praised Gorbachev for breaking down Warsaw Pact resistance to discussions on human-rights issues.

"It is due to him (Gorbachev) that the Vienna concluding document has such an enormous impact on human rights," Zimmermann said.

Both Zimmermann and Soviet delegate Yuri Kashlev agreed both sides got far more out of the conference than either expected, most notably a Soviet agreement to hold new conventional arms-reduction talks.