Prime Minister Robert Mugabe of Zimbabwe yesterday urged the United States to exert "meaningful pressure" on South Africa to cease what he called its "intransigent" opposition to independence for neighboring Namibia.

Speaking to Washington Post editors and reporters at the start of his first official visit here, Mugabe also defended his government's controversial rearrest of six white air force officers acquitted of acts of sabotage. Two of those officers were deported over the weekend.

The prime minister appeared anxious to deflect western criticism of alleged violations of civil and political rights in Zimbabwe, and sought to place its record in the context of internal dissent and external hostility from the white minority regime in South Africa.

Administration officials said they did not expect any surprises during talks scheduled for Mugabe here. He met yesterday with Chester A. Crocker, assistant secretary of state for African affairs, and Secretary of State George P. Shultz and is to meet with President Reagan at the White House this morning.

Mugabe, who led his Zimbabwe African National Union party to power in post-civil war independence elections in 1980, is seen by the United States as a key regional leader with whom it is vital to maintain friendly relations.

"This visit just signifies his importance," one State Department official said.

The attempt to find a peaceful path to independence for Namibia, formerly South-West Africa, which is still ruled by South Africa despite vigorous objections by the United Nations since the 1950s, is a major bone of contention between the United States and Zimbabwe, formerly Rhodesia.

The United States, one of the five western nations that make up the United Nations' so-called "contact group" that is trying to resolve the problem, has linked a Namibian settlement with the withdrawal of Cuban troops from neighboring Angola. The South Africans are more than happy with that demand.

Indirectly attacking the American position, Mugabe told The Post yesterday, "We feel that South Africa has been allowed to be intransigent and we naturally blame the contact group for not having exerted more pressure.

"If the United States wanted to exert meaningful pressure on South Africa, we are confident that South Africa would not continue to be that intransigent," he added. "I believe that if South Africa were spoken to very firmly with threats that the West would not brook any delay on this question, South Africa would proceeed to act positively.

"Our view," Mugabe said of the U.S. linkage policy, "is that as much as we recognize that the United States might feel concerned about the presence of Cubans in Angola that should not be allowed to interfere with resolving the whole question of independence for Namibia."

The Zimbabwean leader was defensive about the rearrest of six white air force officers who were sent back to their cells last week after a judge had dismissed charges that they had plotted to blow up 13 airplanes last year. Two of the officers subsequently were freed and deported last weekend.

A High Court judge acquitted the defendants, all of whom switched to Zimbabwe's armed forces after previously serving the rebel white minority regime of Ian Smith, on the grounds that their signed confessions were extracted through torture and were therefore inadmissible as evidence.

Although they had been cleared, Mugabe said, his government was still convinced of their guilt and links with South Africa.

"We cannot say we cannot exercise our own judgment to determine whether or not someone is a security risk," he said. "Countries which have long achieved their independence and consolidated their security systems sometimes fail to recognize that Zimbabwe is a very young country.

"If people were to look at the fact that even people like Ian Smith, who committed so many atrocities against our people, are free in our country and that they are not being harassed, then they would not accuse us of violating human rights."

Mugabe said that Joshua Nkomo, the opposition leader who returned home last month after fleeing to Britain, was free to organize his Zimbabwe African People's Union for the next elections despite charges that he had previously attemped to overthrow the government.

"He is apparently adjusting now," Mugabe said, "but finds that he has marred his own image . . . . He is a free man. We haven't proscribed his organization, but I wonder how many countries would have behaved as we have done."

The Zimbabwean premier is also to meet here with Peter McPherson, administrator of the Agency for International Development, and with the House Foreign Affairs Committee and invited members of the Senate before continuing on to Canada.