US President George W. Bush said on Wednesday South African President Thabo Mbeki was "the point man" to resolve Zimbabwe's political and economic crisis, and issued a fresh vow to help restore peace to Liberia.
In a warming of relations, the two leaders publicly set aside differences over Mbeki's opposition to the US-led invasion of Iraq and presented a united front in hour-long talks that also touched on AIDS and trade.
President Robert Mugabe's 23-year rule in Zimbabwe had been expected to expose divisions, but Bush said he would not second-guess Mbeki's policy of "quiet diplomacy" on the issue.
"The president is the point man on [Zimbabwe]," said Bush, on a first trip to sub-Saharan Africa as president that underlines a rethink of the continent's strategic importance.
"He believes he's making good progress. I think Mr Mbeki can be an honest broker," Bush told a news conference in the lush grounds of a luxury government guest house in Pretoria.
Bush, under growing pressure from across Africa to send US troops to help enforce a fragile ceasefire in Liberia's 14 years of civil war, said he was still assessing the issue but would definitely play a role in peace efforts.
"The president [Mbeki]...asked whether or not we'd be involved [in Liberia] and I said, `Yes, we'd be involved,'" Bush said.
Bush, who gave a similar pledge to West African leaders on Tuesday, has sent more military experts to Liberia to help decide on any peacekeeping role. In their last African foray, US troops had to make a bloody exit from Somalia 10 years ago.
US Secretary of State Colin Powell, accompanying Bush, signalled Washington was actively engaged in the peace drive by suggesting the arrival of peacekeepers should coincide with Liberian President Charles Taylor's departure from office.
Zimbabwe moved up Washington's Africa agenda last year when Mugabe won re-election in a poll branded as fraudulent by the opposition and Western states.
Zimbabwe suffers chronic food shortages and 70 percent unemployment. Critics blame Mugabe, but he says it is due to sabotage by opponents angry over his seizure of white-owned farms for redistribution to landless blacks.
Bush, whose reassessment of Africa was prompted by growing US reliance on the continent's oil and intelligence that al-Qaeda could use it as a hideout, said Mbeki was working hard on Zimbabwe.
Mbeki said he and Bush were "absolutely of one mind" about how to deal with Zimbabwe.
About 100 Zimbabwe opposition supporters waved placards outside the US embassy as hundreds of South African activists took to the streets for Bush's visit -- some praising him as a messenger of hope, others declaring him a dangerous warmonger.
While many South Africans value promises of aid, the Anti-War Coalition held a demonstration over Iraq that demanded a "people's tribunal against the warmongers."
Bush was kept well away from demonstrations as police threw a tight security net across Pretoria.
The president, also due to visit Botswana, Uganda and Nigeria, wants to boost democracy and economic development in Africa, highlight a US$15 billion program to fight AIDS and promote a US$100 million initiative against terrorism.