LONDON -- Prime Minister Margaret Thatcher, announcing that the Argentine commander on South Georgia had formally surrendered to British forces early today, called on Argentina to resume negotiations on the disputed Falklands Islands.
She made the announcement in a report to Parliament on the British recapture Sunday of the isolated island 800 miles east of the Argentine-occupied Falkland Islands.
Mrs. Thatcher said British forces captured about 180 Argentines, including 50 military reinforcements aboard the submarine Santa Fe which was attacked and disabled by British helicopters shortly before the main assault.
The Argentine prisoners will be returned home, Mrs. Thatcher said, just as Argentina repatriated British marines captured during the invasion of the Falkland Islands April 2 and South Georgia the next day.
The formal surrender of the Argentine forces came at 5 a.m. EDT, she said.
Noting that Argentine diplomats have said the British attack broke off negotiations, Mrs. Thatcher said, 'As the task force approaches the Falklands, the urgent need is to speed up negotiations, not to slow them down.'
She gave a brief description of the capture of the South Georgia ports of Grytviken and Leith, and the attack on the submarine Santa Fe off the coast.
She said British troops used 'minimum force' and suffered no casualties. She made no comment on Argentine casualties, but defense officials said one soldier had to have his leg amputated because of injuries he suffered.
Mrs. Thatcher said the British action torecapture South Georgia, seized by Argentina April 3, was 'fully in accordance with the right of self defense under Article 51 of the U.N. charter.'
'The repossession of South Georgia in no way alters our determination to achieve a negotiated settlement and to secure the implementation of Security Council resolution 502,' she said. The resolution called for a cease-fire, withdrawal of Argentine troops from the Falklands and negotiations on their sovereignty.
She said British troops now are trying to contact a small group of British scientists known to be on South Georgia.
'We shall evacuate them, if they wish,' she said.
Before making her House of Commons statement Mrs. Thatcher met with her war cabinet.
In Washington, the foreign ministers of the Organization of American State met to hear Argentine Foreign Minister Nicanor Costa Mendez's expected request for aid against Britain.
Under the 1947 Rio treaty, 21 nations of the Americas, including the United States, pledged to aid each other in the case of outside aggression. Earlier, Costa Mendez met with Secretary of State Alexander Haig, whose mediation efforts have been frozen by the British attack.
The Sunday attack gave Britain a potentially valuable base for an eventual counterattack on the Falkland Islands and also provided a badly needed morale boost to a nation still smarting from the loss of its South Atlantic colonies on April 2.
'If we surrendered British territory and British citizens to Argentina,' the Daily Express said, 'we would have given way to armed aggression, have abandoned all principle and honor, have forfeited all influence and destroyed our national self-respect.'
The requisitioned ferry Norland was scheduled to leave Britain today with another 900 paratroopers to join the 3,500-4,000 troops already with the task force. Another requisitioned container ship was leaving with more helicopters.
British warships and helicopter-borne troops overpowered the small Argentine force on South Georgia early Sunday and left one of Argentina's four submarines burning.
South Georgia's recapture gave Britain's naval task force anchorages in the harbors at Grytviken and Leith outside the range of Argentine planes. It also gave the troops a chance to stretch their legs after nearly three weeks at sea.
But the island, covered with glaciers and high peaks, is too rugged for an air strip, leaving Britain's nearest airfield 3,000 miles away on Ascension Island.
The London Times, which called for Washington now to back Britain, defended the attack as self-defense and said the task force could 'not to be left indefinitely cruising around the islands.'
The attack was announced Sunday evening by Defense Secretary John Nott with Mrs. Thatcher standing beside him on the steps of her No. 10 Downing St. office.
'Be pleased to inform Her Majesty that the White Ensign flies alongside the Union Jack on South Georgia,' Nott read the brief message from the unidentified commander of the operation. 'God Save the Queen.'
South Georgia was captured April 3 by a large Argentine force that overpowered a tiny British garrison of 22 marines. Crack British troops took only two hours Sunday to reclaim it, without any British losses, Nott said.
The Financial Times, while generally supportive, urged the government to offer to go to the International Court of Justice or to accept UN trusteeship of the islands. The Guardian newspaper noted Britain had been discussing sovereignty with Argentina for years.