MOSCOW, JULY 7 -- Soviet leader Mikhail Gorbachev met West German President Richard von Weizsaecker today and disputed suggestions that the question of East-West German reunification "remains open."

Weizsaecker, who arrived yesterday on a visit, had said Germans will never cease to believe that they are "one nation" despite the division of their land. But Gorbachev reminded Weizsaecker of the 1970 treaty West Gemany signed with Moscow to respect the "territorial integrity" of present European states.

He also praised Bonn's 1970 treaty with Poland settling Poland's border along the Oder and Neisse rivers. The two treaties led to the era of detente.

"But when we hear it said again and again that the German question remains open, that not everything is clear about the eastern lands and that Yalta and Potsdam are not valid, this gives rise to doubts whether the leadership of the Federal Republic of Germany intends to adhere to this treaty," Gorbachev said.

The Yalta and Potsdam agreements, reached near the end of World War II by Britain, the Soviet Union and the United States, increased the size of Poland and reduced Germany.

On the second day of Weizsaecker's stay in Moscow, there still was no word on whether West German pilot Mathias Rust, 19, might be released from prison where he has been held since landing his private plane near the Kremlin on May 28.

"We should really be patient and wait a bit longer to see how events will develop," Soviet Foreign Ministry spokesman Boris Pyadyshev said. Pyadyshev ridiculed a suggestion that Rust's release could be used as a measure of the success of Weizsaecker's visit.

"This is shortsighted," he said. "Such an overemphasis on this case cannot contribute to the successful outcome of the visit, neither to the successful further development of Soviet-West Germany relations in general."