Vice President Walter Mondale told his Nigerian host yesterday that the Soviet Union's invasion of Afghanistan, putting the superpower close to Persian Gulf oilfields, is a threatening development that "is dangerous to civilization itself."

Stepped-up American Military moves in the Horn of Africa, Mondale said, have been made to "preclude a nuclear confrontation" between the United States and the Soviet Union in the Persian Gulf region, Washington Post correspondent Leon Dash reported.

Mondale made his comments during a brief press conference here with Nigerian reporters immediately before leaving to return to Washington.

The high point of activities was the signing of an extensive bilateral trade and cooperation statement by Mondale and Nigerian Vice President Alex I. Ekueme. The joint communique between the two governments envisioned increased trade, transfer of American oil production technology to Nigeria, development of alternative energy sources, a wideranging agricultural program, scientific exchanges, and educational programs. It also laid the foundation for negotiations on a bilateral trade agreement.

When a Nigerian reporter asked Mondale if he had run into any suspicion toward America while in Nigeria, Mondale said. "I didn't see that suspicion reflected . . . You cannot have reached an agreement like the one that was announced this morning without trust."