Lawrence Jackson, Associated Press
President Bush walks through a ceremonial arrival cordon with Tanzanian President Jakaya Kikwete at the State House in Dar es Salaam, Tanzania, on Sunday.

DAR ES SALAAM, Tanzania — President Bush rejected proposed Democratic changes to his prized AIDS relief program, issuing a challenge Sunday to Congress to "stop the squabbling" and renew it as is. Tanzanian leader Jakaya Kikwete made an impassioned appeal for the same thing, saying thousands in his country would orphan their children if U.S. lawmakers do not act.

There is broad support in the Democratic-controlled Congress for the anti-AIDS spending that has become the largest-ever international health initiative devoted to one disease, so there is not much danger of failing to continue it.

But with the program expiring this year, a political and ideological showdown is brewing in Washington over the initiative's terms and size. Bush hopes that putting real, grateful faces on the program — moms and dads controlling the disease and children who were born HIV-free to infected mothers, all because of U.S.-funded treatment — would strengthen his hand in the debate.

The president's three-night stay in this vast East Africa nation takes him to a part of the continent that is important in the U.S. fight against terrorism. The bombed-out former U.S. Embassy in Dar es Salaam still stands as a stark reminder of deadly attacks in Tanzania and Nairobi, Kenya, in 1998.

The visit to Tanzania is the longest of Bush's six-day African trip and longer than usual for the president anywhere. The stay and the celebration of a new five-year $698 million U.S. aid pact were intended as goodwill messages to Tanzania's large Muslim population.

It seemed to work. In contrast to the protests that often greet him at home and abroad, Bush repeatedly received enthusiastic receptions in Tanzania.

Thousands of people lined his motorcade route from the airport Saturday night. A large and spirited crowd waved U.S. and Tanzanian flags Sunday as he walked into the graceful, oceanfront State House for meetings with President Kikwete.

Thousands more people crowded along Dar es Salaam's dusty and rutted streets as Bush went from event to event. Special local cloth was woven in honor of Bush's visit; his picture was emblazoned across ever-present shirts and sarongs.

A billboard advertisement in downtown for a Kilimanjaro Casino poker tournament offered a coincidental but telling message: "A little bit of Texas in Dar," it said.

"Different people may have different views about you and your administration and your legacy," said a grateful Kikwete after he and Bush signed the aid deal. "But we in Tanzania, if we are to speak for ourselves and for Africa, we know for sure that you, Mr. President, and your administration, have been good friends of our country and have been good friends of Africa."

Democratic presidential candidate Barack Obama, who is black and whose father was Kenyan, is a sensation in Africa. Africans say they avidly follow Obama's campaign to succeed Bush.

But Bush seemed surprised that Obama's name would come up during this victory-lap journey that is celebrating some of his only foreign policies that make him popular.

"It seemed like there was a lot of excitement for me, wait a minute. Maybe you missed it," he joked during a news conference, speculating that a question about Obama was put to Kikwete instead of him because it was well known that "I wouldn't answer."

Kikwete appeared to get the hint, declining at Bush's side even to discuss the prospect of a man with African roots becoming president of the United States.

"I don't think I can venture into that territory, either," Kikwete said. "The U.S. is going to get a new president, whoever that one is. For us, the most important thing is, let him be as good friend of Africa as President Bush has been." Bush's term ends next January.

The President's Emergency Plan for AIDS Relief, known as PEPFAR, has raised the number of Africans on anti-retroviral treatments from 50,000 to 1.2 million.

Democrats want to strip requirements that one-third of the money go to abstinence-until-marriage programs and that some groups sign anti-prostitution pledges.

Some Democrats also say that Bush's request for $30 billion over the next five years, twice his original commitment of $15 billion, is too little, and would merely continue the program at the current year's ramped-up levels. Congress has put nearly $19 billion into the program so far.

Republican leaders say the Democratic changes could derail renewal of the program, and Bush made clear he agrees.

"I understand there's voices on both ends of the political spectrum trying to alter the program. I would ask Congress to listen to leaders on the continent of Africa, analyze what works, stop the squabbling and get the program reauthorized," the president said, the caws of peacocks occasionally punctuating remarks delivered in the blazing sun. "I happen to think the current policy is reasonable. After all, it's working."

Later, Bush said that Amana Hospital was the best exhibit he could imagine for his argument. Strolling through the complex of low-slung buildings and sun-drenched courtyards, Bush met HIV-positive patients and doctors in the facility's AIDS treatment wing, funded in part with money from his AIDS program.

"I'm very lucky," said Tatu Msangi, who was tested for HIV while pregnant, received treatment and delivered a healthy baby, Faith, who sat in her lap while she spoke. "Me and Faith have a bright future ahead."

Later, after separate events in Dar es Salaam to promote the program, first lady Laura Bush sounded less worried than her husband about its legislative future. "I don't think there will be a problem," she told reporters.

Kikwete said the program has allowed thousands of children such as Faith to avoid suffering the deaths of parents. "My passionate appeal is for PEPFAR to continue," he said.

Though Tanzania is one of the poorest countries in the world, it is gaining international investors, has among the best growth rates in sub-Saharan Africa and, as the home to striking Mount Kilimanjaro and the Serengeti National Park, is seeing tourism rise. There is little internal strife, though there are some worries about the political ambitions of semiautonomous Zanzibar, and Tanzania also is absorbing refugees from the postelection fighting in Kenya.

The U.S. aid deal, approved in September and signed in a ceremony Sunday, is through the Millennium Challenge Corporation. That Bush initiative limits U.S. development assistance to nations that embrace democracy and free markets, fight corruption and invest in education and health. The Tanzanian deal is the largest so far in the program and is focused on helping to build roads, make electricity more reliable, and increase access to safe drinking water.

"Our trip here has exceeded my expectations," Bush said in a dinner toast at the State House. On the lawn afterward, the leaders were treated to an energetic, whooping performance by traditional African dancers with feathers, bells, drums and flutes.