In a possible sign of the seriousness of Mandela's condition, daughter Zenani Mandela — South Africa's ambassador to Argentina — arrived at the hospital to see her father. Former wife Winnie Madikizela-Mandela also visited.
Mandela's doctors briefed President Jacob Zuma on the former president's health late Monday, the president said in a statement. Mandela remained in serious but stable condition, it said.
School children gathered outside his home in a Johannesburg suburb on Tuesday and sang songs expressing hope the former president would recover.
Mandela, the leader of South Africa's anti-apartheid movement, spent 27 years in prison during white racist rule. He was freed in 1990, and then embarked on peacemaking efforts during the tense transition that saw the demise of the apartheid system and his own election as South Africa's first black president in 1994.
His admission to a hospital in Pretoria, the capital, is Mandela's fourth time being admitted to a hospital for treatment since December. His last discharge came April 6 after doctors diagnosed him with pneumonia and drained fluid from his lung area.
At Johannesburg's Apartheid Museum on Tuesday, visitors walked through an exhibit showcasing the life of Mandela amid a feeling in the country that this hospitalization may be more serious than previous ones.
"All these admissions to the hospital has been preparing us for this, that this may be the end, and that is enough to tell us this is very serious," said Father Victor Phalana of Cathedral of the Sacred Heart in Pretoria, who was touring the museum with two Catholic priests from Uganda.
Outside Mandela's Johannesburg home, school children from the Rainbow Hill Christian School sang words of encouragement. "We love you Mandela ... get well, get well," they sang.
Lebogang Serite, a 12-year-old student at the school, said she "couldn't be in a white people's school" had it not been for Mandela's anti-apartheid efforts. "He means a lot to me because he fought for the country. I couldn't be in a white people's school," she said.
"I know that if he was able to speak, he was going to play with them today. Unfortunately, wherever he is, he's not well, but I know that he worked very, very hard for us. That's why we are here," said Mama Zodwa, a 57-year-old teacher from the school.
On Monday a foundation led by retired archbishop Desmond Tutu described Mandela as an "extraordinary gift" and offered prayers for his comfort and dignity. The Desmond and Leah Tutu Legacy Foundation described Mandela as "the beloved father of our nation."
Mandela is seen by many around the world as a symbol of reconciliation because of his peacemaking role when white racist rule ended in South Africa. Tutu, 81, was also vigorous campaigner against apartheid, which ended when all-race elections were held in 1994 and Mandela president.
Like Mandela, Tutu was awarded the Nobel Peace Prize for his efforts on behalf of his compatriots. Mandela shared his prize in 1993 with F.W. de Klerk, the last president of the apartheid era.
In its brief statement on Mandela's health, the presidency said Zuma "reiterates his call for South Africa to pray for Madiba and the family during this time," referring to Mandela by his clan name.
Mandela has been particularly vulnerable to respiratory problems since contracting tuberculosis during 27 years as the prisoner of the white racist government. The bulk of that period was spent on Robben Island, off the coast of Cape Town where Mandela and other prisoners spent part of the time toiling in a stone quarry.
He was freed in 1990, and then embarked on peacemaking efforts during the tense transition that saw the demise of the apartheid system and his own election as president in 1994.
The former leader retired from public life years ago and had received medical care at his Johannesburg home until his latest transfer to a hospital.
___ Associated Press Television News reporter Bongani Mthethwa and Associated Press reporter Wandoo Makurdi in Johannesburg contributed to this report.
North Korea said it wasn't sending its officials to Seoul for the two-day meeting that was to begin Wednesday because the South had changed the head of its delegation, Kim Hyung-suk, a spokesman for Seoul's Unification Ministry, told reporters in a briefing. The ministry is in charge of North Korea matters.
There had been hope that the talks on reviving two high-profile economic cooperation projects would allow the countries to move past a relationship marred by recent North Korean threats of nuclear war and South Korean vows of counterstrikes. But the collapse over what's essentially a protocol matter is testament to the difficulty the countries have in finding common ground.
South Korea had originally wanted a minister-level meeting between the top officials responsible for inter-Korean affairs, but Pyongyang wouldn't commit to that. The last minister-level meeting between the Koreas occurred in 2007.
When Seoul told Pyongyang on Tuesday that it was sending a lower-level official than it had initially proposed in preparatory talks, North Korea said it would consider that a "provocation," Kim said.
The cancellation of talks arises partly from misunderstandings that the sides have about who is equivalent to whom in power between their largely different political systems, Koh Yu-hwan, a North Korea scholar at Seoul's Dongguk University, said.
"The two sides are offended by each other now. The relations may again undergo a cooling-off period before negotiations for further talks resume," he said.
North Korea did not immediately issue its own statement about the canceled talks.
The talks were set up in a painstaking 17-hour negotiating session Sunday, but the rivals had set aside the issue of who would lead North Korea's delegation. Kim said that on Tuesday, North Korea offered to send a senior official of the Committee for the Peaceful Reunification of Korea as chief delegate, and Seoul said it would send its vice unification minister as chief delegate.
South Korea had previously proposed sending its unification minister. After it announced the vice minister would go instead, North Korea said it wouldn't send anyone and that "all responsibility is entirely on South Korea," Kim said. He added that Seoul is still open to talks if North Korea reconsiders.
The main goal of the planned talks had been to see if the Koreas could restore economic projects that were born in the "sunshine era," a 10-year period ending in 2008 when South Korea was ruled by liberal presidents who shipped large quantities of aid to Pyongyang as they sought to improve ties. The last of those projects, a North Korean factory complex run with North Korean workers and South Korean managers and capital, shut down this spring.
North Korea also wanted Seoul to restart an era of rapprochement by commemorating past joint statements on reunification and joint economic cooperation efforts. But Seoul balked at this; it has demanded apologies for past bloodshed before allowing such exchanges.
North Korea's interest in talks followed its longstanding cycle of alternating between provocative behavior and attempts to seek dialogue in what analysts say are efforts to win outside concessions.
After U.N. sanctions were strengthened following North Korea's third nuclear test in February, the country, which is estimated to have a handful of crude nuclear devices, threatened nuclear war and missile strikes against Seoul and Washington. North Korea has also conducted recent nuclear tests and long-range rocket launches.
Some observers believe Pyongyang was trying to ease ties with Seoul, Tokyo and Beijing as a way to win coveted talks with Washington, which it believes could grant it aid and security guarantees.
South Korean President Park Geun-hye has made trust-building with Pyongyang a hallmark of her nascent rule, even as she vows strong counterstrikes to any North Korean attacks.
There was skepticism in Seoul about the talks even before they collapsed.
"We cannot be overly hopeful about inter-Korean relations, which reached a new low not long ago," the conservative Korea JoongAng Daily said in an editorial Tuesday. "We have experienced numerous setbacks during past talks with Pyongyang."
___ AP writer Foster Klug in Seoul contributed to this report.
WASHINGTON (AP) - President Barack Obama is inviting law enforcement, labor and business leaders to the White House to show they support an immigration overhaul.
The White House says Obama will speak Tuesday about the economic and national security benefits of a bipartisan bill. The first votes in the full Senate are scheduled for Tuesday afternoon.
Obama is highlighting the disparate groups that are backing the bill even though they've opposed each other on immigration in the past.
U.S. Chamber of Commerce Tom Donahue will join Obama, as will AFL-CIO President Richard Trumka. Democratic Mayor Julian Castro of San Antonio and Bush-era Commerce Secretary Carlos Gutierrez also will be on hand. Faith leaders will be represented as well.
The bill creates a path to citizenship for 11 million people in the U.S. illegally.