Archbishop Desmond Tutu, in his first day as archbishop of the Anglican Province of Southern Africa, today waded through the ankle-deep mud and sewage of the squatter shantytown of Crossroads and found himself embroiled in a controversy between U.S. civil rights activist Coretta Scott King and militant South African black nationalists.

Because of King's planned meeting with South African President Pieter W. Botha, two prominent black nationalist leaders, Winnie Mandela and the Rev. Allan Boesak, reportedly have balked at meeting with the widow of the United States' best-known civil rights activist, Martin Luther King Jr.

Wearing sunglasses and a peasant watchman's cap, Tutu, accompanied by the Most Rev. Robert A.K. Runcie, archbishop of Canterbury, toured Crossroads, where last May and June upwards of 70,000 black squatters were driven out of their makeshift shacks in a government-backed campaign of mass resettlement.

Shadowed almost constantly by security forces in armored trucks, Tutu and Runcie spent about an hour in Crossroads, trailed by carloads of journalists in one of the most elaborately organized media events in the western Cape Province in recent years.

Tutu, Cape Town's first black archbishop, used the occasion to make a plea to Botha to commute the death sentences of three black nationalists scheduled to be hanged Tuesday in a Pretoria prison for their involvement in terrorist activities.

Later, Tutu repeated his tour of Crossroads for King, showing her coils of razor wire surrounding the squatter area which he called "South Africa's Berlin Wall."

King said the squalid resettlement camp "really defies the imagination," adding, "Evil and injustice cannot reign forever . . . . It will have to give way."

However, the Crossroads tour by the two archbishops was overshadowed, in part, by a growing controversy over King's plans to meet with Botha, who to many blacks is a symbol of the government's attachment to the policy of racial separation and continued white rule.

King also has planned a controversial meeting with Mangosuthu Buthelezi, the Zulu tribal chieftan who has sought to reach an accommodation with Botha's government and who is viewed as a government collaborator by many militant blacks.

Mandela's confidants said that a meeting with King would be impossible as long as she insisted upon seeing Botha. Boesak yesterday told reporters that if King met with the president, he would not meet with her, because, he said, Botha's "hands are literally dripping with the blood of our children."

Mandela is the wife of the imprisoned African National Congress leader, Nelson Mandela, and Boesak is the president of the World Alliance of Churches and was Cape Town's best-known antiapartheid activist until the arrival here of Tutu.

Tutu, who angered many militant black nationalists because he met twice with Botha, said, "I've not been involved in that . . . . Who she sees is up to her. I'm not involved in her private agenda."

King, in a brief interview at the posh Mount Nelson Hotel, where she is staying with an entourage of security guards and public relations advisers, said her plans were unchanged.

"It's important to dialogue with all sides. We'll have to see how things work out, but it's really important to have dialogue with people who hold opposing views," King said.

She added, "It's not an easy thing to do. We're trying to begin the process." When asked whether she would meet with Mandela, King added, "We look forward to that. We'd like to meet with her. She's on the list."

However, one of King's advisers, Ofield Dukes, asked about the flap over the meetings with Botha, Mandela and Boesak, said, "It's a minefield," adding that the planned meeting with Botha was being "reassessed."

As the archbishops toured Crossroads in a winter drizzle, Runcie chatted with Crossroads residents. He told reporters, "On television, you don't sense the daily squalor, the flies, the filth, the dehumanizing way people are just thrown together. It's so much more dramatically squalid than I had expected. It's the detail that's so horrifying."

Runcie said he was appalled by the squalor of Crossroads, and called on the white-minority government of South Africa to make more effort to solve the country's "clear social problems."

"You've got whole families out here who've never had jobs. The barbed wire, all the security vehicles, seem to me to say that the government is not directly interested in solving the problems," said Runcie, the spiritual leader of 65 million Anglicans worldwide.

Tutu used the occasion to appeal to Botha to grant a reprieve to three ANC members who are scheduled to be hanged Tuesday in Pretoria. A reprieve, Tutu said, would "create a climate that would make people want a little more to negotiate."

The archbishop said that if the executions take place, they will "just be another example of the intransigence of this government . . . . They act as if they are not dealing with human beings [but] one still hopes that the milk of human kindness flows among them."