"I believe that if both sides walked towards each other, they will be able to see a healthy and stable China-US relationship, China's UN ambassador said.
In his speech, Xi said disputes among countries "need to be handled through dialogue and cooperation" and urged world leaders to eschew "confrontation and exclusion."
Gorbachev, 90, has spoken about the coup with bitterness, describing it as the fatal blow to the Soviet Union.
The Thresher was the first of a new class of attack submarines that could travel farther and dive deeper than any previous sub.
Among the invited guests of honor was 98-year-old U.S. pilot Gail Halvorsen, who dropped hundreds of boxes of candy on tiny parachutes into West Berlin during the blockade.
In a speech to students at Geneva University, Antonio Guterres presented a new disarmament agenda to face challenges emerging in a world where "Cold War tensions have returned."
A former colonel with Russian military intelligence, Skripal was sentenced to 13 years in jail in Russia in 2006 on charges of spying for Britain.