Updated

US President Barack Obama and his predecessor George W. Bush will team up Tuesday for a rare meeting, on foreign soil in Tanzania, to honour victims of terrorism.

Obama flew into the country on the last leg of his three-nation Africa tour on Monday while Bush will be in the country for a forum of regional First Ladies, hosted by his wife Laura, which Michelle Obama will also attend.

The two presidents will meet to lay wreath at a memorial to 11 people killed when Al-Qaeda bombed the US embassy in Dar es Salaam in 1998.

Obama said the meeting would give him a chance to thank Bush again for pioneering an emergency plan to fight HIV/AIDS, tuberculosis and malaria, during his presidency, credited with saving millions of lives.

"This is one of his crowning achievements," Obama said at a press conference with Tanzanian President Jakaya Kikwete.

"Because of the commitment of the Bush administration and the American people, millions of people's lives have been saved," Obama said.

Obama also noted that the program had continued to be financed during his administration and it had evolved and was now serving four times as many people than when it started a decade ago.

The current US president came to power after a 2008 election campaign in which he mounted stinging attacks on Bush's record on foreign policy and the economy.

But Bush, a Republican, has stayed largely out of sight since he left office in 2009, having vowed not to criticise his Democratic successor in public, and Obama aides say the two men have a good personal relationship.

Obama and Bush last met when the president attended the opening of the Republican's presidential library in Dallas in April.

The bombing of the US embassy in Tanzania was timed to coincide with a separate attack on the US embassy in the Kenyan capital Nairobi that left 213 dead and several thousand wounded.