South Korea's foreign minister reiterated his government's view yesterday that it cannot force Tongsun Park to return to the United States to co-operate with investigation of Korean influence-buying efforts on Capitol Hill.

The minister, Park Tong-chin, was asked yesterday whether Tongsun Park was likely to return to this country soon: "It's up to him," the South Korean official responded.

The foreign minister spoke briefly to reporters after discussing the Tongsun Park case with Secretary of State Cyrus R. Vance.

Tongsun Park was indicted here last month on charges that he tried to bribe members of Congress. Park is in Seoul and has refused to the United States to face the charges.

The United States and South Korea have no extradition treaty. But Washington has made several diplomatic approaches - including a personal letter from President Carter to President Park Chung Hee - to try to convince the South Korean government to send Park back here.

These efforts are based on the State Department's conviction that the Seoul government could force Tongsun Park to return to the United States if it wanted to.

The South Korean government has denied that, and the foreign minister's comment yesterday indicated that it has not abandoned that position.

Accordingly, Foreign Minister Park, in answer to a reporter's question, said yesteday he did not think the Tongsun Park dispute was any closer to a solution as a result of his meeting with Vance.

Vance's public information office released no details of the meeting, but said Vance and Park Tong-chin would "stay in touch."

Yesterday morning, before the Vance-Park meeting, President Carter told Democratic congressional leaders he "has done everything he humanly could do" to help investigators get testimony from Tongsun Park, according to House Speaker Thomas P. (Tip) O'Neill (D-Mass.).

O'Neill and other members of Congress were quoted by United Press International as saying that Carter told them that a strong message had been sent to the South Korean president, but no positive answer had been received.

The UPI report also said that O'Neill had cautioned Carter against a proposal that the United States leave its military equipment behind when American troops are withdrawn from South Korea.

O'Neill was reporterd as warning the President that such a proposal might fare badly in Congress right now because of the various investigations of Korean influence-buying.

The Korean foreign minister said his talks with Vance did not cover Kim Hyung Wook, a former chief of the Korean Central Intelligence Agency now living in the United States.

Seoul newspapers have suggested that South Korea might indict Kim and demand his return to Korea, just as the United States has demanded Tongsun Park's return here.

If Kim were indicted in South Korea, the government there might ask for a "swap" will this country, Kim for Tongsun Park.

The Carter administration might then face a dielmma: It would risk severe criticism if it sent Kim back to face punishment in Seoul, but it might be on weaker ground in demanding Park's return here if Kim does not return to Korea.

A State Department official said the department is aware of the rumors in Seoul about an indictment of Kim, but would have no comment.