MOSCOW (AP) _ South African Foreign Minister Pik Botha said Friday he envisioned vast opportunities for cooperation with the Soviet Union and the resource-rich Russian republic.

The Soviet Union severed diplomatic relations in the mid-1950s over South Africa's policy of apartheid. Moscow was the main supporter of the African National Congress' guerrilla campaign, which ended in 1990.

Botha said South Africa's representation in Moscow would be increased, but did not say if full diplomatic relations would be established.

He said there were ''no obstacles'' to renewing ties on the South African side and added: ''I stand ready to open an office in St. Petersburg tomorrow and in Moscow the day after tomorrow.''

With the fall of communism in the Soviet Union and the wane of apartheid in South Africa, ''I don't see any reason why we should be apart anymore,'' he said at a news conference in a Moscow hotel.

''I am convinced from what I've learned that there is a vast scope for close cooperation,'' Botha said.

The African National Congress, which has had a diplomatic mission to the Soviet Union for more than 20 years, said before Botha's arrival that the visit was premature.

Before Moscow, Botha visited the Baltic states of Latvia, Estonia, Lithuania, which gained their independence from the Soviet Union following the failed August coup. Botha said South Africa had agreed to establish full diplomatic relations with all three countries.

Botha was expected to meet with Soviet Foreign Minister Boris Pankin on Saturday and there was a possibility he would meet with Soviet President Mikhail S. Gorbachev.