A diplomatic limousine swung into the drive of the American official residence, carrying the elegant wife of a European ambassador along with boxes of soap, towels, and men's underwear.

It was another of the daily deliveries that pour out of Western embassies, pile up at the home of the United States' chief diplomat here, and are then ferried across town to the U.S. interests section where 383 Cubans have been holed up for 14 days.

The Western diplomats in this country of scarce consumer goods are volunteering to help with the complex logistics of providing daily meals, toiletries and clean clothes for the nearly 400 refugees as signs grow they may have to stay inside the mission for quite a while.

No talks about the departure of the Cubans have been held between Washington and Havana since Cuba abruptly halted them 11 days ago, demanding that all the men inside the mission be handed over to the local authorities. The Cuban government apparently wants the Cubans inside the building for propaganda purposes at least until Saturday, when it plans to mobilize 5 million people in the largest ever anti-American demonstration.

But President Fidel Castro is expected to hold out for much higher stakes. Cuban sources said last week that Castro wants to use the exodus of Cuban refugees to Florida and the virtual hostages in the mission as pressure points to start talks about Havana's main grievances with the United States -- the economic embargo and the U.S. base at Guantanamo.

The Cubans at the mission had been lined up there seeking visas when assailants, including government workers, attacked them. They fled inside and the United States has said it will not turn them back into the street.

More than 35,000 Cubans have now left by boat from the port of Mariel and some Cuban sources have said that 250,000 may want to flee to the United States if given the opportunity. As things stand now, Cuba will do nothing to stop that, the sources said.

In the past few days, Cuban officials have permitted American reporters to pass through the barricades that cut off normal access to the American mission along Havana's seaside boulevard.

The U.S. diplomats, however, have barred journalists from entering, reportedly for fear of appearing to seek publicity that may irritate Havana and jeopardize supplies for those inside.

U.S.-Cuban relations, now severely strained, have been cool since Castro started sending combat troops to Africa in force in early 1976. Although the Carter administration initially accelerated efforts to negotiate a resumption of full diplomatic ties, they remain at the same level as when the interest sections opened in Havana and Washington in September 1977.

Diplomats familiar with the situation in the interests section of the Swiss Embassy, the former U.S. Embassy building here, said that life on the large ground floor of the seven-story building has been surprisingly smooth.

One explanation offered was the fact that almost all the men have served long prison sentences, are used to discipline and to being stuck indoors.

Classes have been organized for the 12 children inside who at times paddle in the patio fountain. The six U.S. Marines reportedly operate as handymen and have built beds and two extra showers in the building that had only one.

The old basement staff cafeteria, closed since diplomatic relations were broken almost 20 years ago, has reopened. Its large kitchen and eating area are used by the refugees, who wait in line with chits for meals. Their food consists of canned meats, milk, vegetables, sandwiches, whatever the Western diplomatic wives have brought from their own stocks or from the "Diplo" -- as the store that Cuba provides for diplomats is called.

Leader of this indoor refugee camp is Wayne Smith, who heads the interests section. He was also the last U.S. official to leave Cuba when relations were broken in 1961.

Smith, a tall, bearded Texan, has a reputation among his foreign colleagues of being forthright, keeping cool and having a seasoned understanding of Cuban affairs.

Even Cuban officials who are deeply resentful of Washington's past and present policies have privately told Westerners they see Smith as an effective diplomat. He speaks good Spanish and has succeeded in keeping open channels of communication.

The mission staff of 20 reportedly is more strained by the recent sharp anti-American attacks in the official Cuban press than by taking care of the refugees.

[In Washington, the State Department announced that 17 Americans, including diplomats and dependents, were being flown to Miami because of the "virulent" anti-American campaign, Associated Press reported.]

Following a recent article that blamed the CIA for a fire in a large Havana nursery (that caused no casualties), the tires of a U.S. diplomat's car were flattened and people in the street yelled "Assassin," at another envoy.

At the refugee port of Mariel, the bay is still chockfull of American boats whose captains continue to haggle with Cuban officials about how many and what kind of refugees they will take back to Florida.