Cuban President Fidel Castro arrived today for talks with Soviet leaders that are expected to focus on his recently completed tour of Africa.

His plane landed at Vnukovo, the airport near Moscow that is used for important visitors. When he emerged he was hugged by Communist Party leader Leonoid Brezhnev and by Soviet President Nikolai Podgorny who had returned only two hours earlier from his own trip to Africa.

Also on hand for Castro's arrival was Soviet Premier Alexei Kosygin and Foreign Minister Andrei Gromyko. The rank of the welcoming group and the warmth of its welcome indicated that Moscow is placing considerable importance on the visit of the Cuban leader.

Castro's visit was described as unofficial, but the failure of the Soviet press to mention it led some Western observers to conclude that the trip was arranged hastily. Castro had spent the previous three days in East Germany.

The talks with Castro are expected to deal with ways to aid black nationalists in fighting white-minority governments in southern Africa.

Podgorny visited Tanzania, Zambia and Mozambique, three of the "front-line" states in the campaign by black nations to end white rule in the southern part of the continent. He made a surprise visit to Somalia, a close Soviet friend in East Africa.

Castro visited the same four countries, plus Algeria and Ethiopia.