US Secretary of State Hillary Clinton has urged Angola to hold credible elections and address the country's past poor human rights record.

Mrs Clinton was speaking after talks with senior Angolan officials in Luanda - the third stop of her African tour.

Presidential polls in Angola were due to be held this year, but delays mean they are likely to be held in 2010.

Mrs Clinton will meet Angola's leader on Monday to discuss closer trade links with the oil-producing nation.

Speaking in Luanda, Mrs Clinton praised Angola for its progress since the end of a devastating civil war in 2002.

She said she was "encouraged" by Angola's "peaceful and credible" parliamentary elections last year, although she stopped short of calling them free or fair.

She also reiterated the need for good governance and strong democratic institutions and said it was important to be vigilant against corruption.

China factor

Mr Clinton was speaking after meeting Angolan Foreign Minister Assuncao Dos Anjos and the country's senior oil executives.

Angola has been heavily criticised for its management of oil revenues, the BBC's Louise Redvers in Luanda reports.

Despite Angola's enormous wealth, two-thirds of the population live on less than $2 a day, our correspondent says.

In Luanda, Mrs Clinton signed a memorandum of understanding with American oil giant Chevron and the US Agency for International Development (USAid) to promote investment in Angola's agricultural sectors like coffee and bananas.

Asked about China's growing influence in Angola, Mrs Clinton said she was not interested in what other people were doing in Angola because her focus was on what the US was doing.

Last year, Angola overtook Saudi Arabia as China's leading source of crude oil.

The US gets about 7% of its oil from the southern African country.

On Monday, Mrs Clinton is expected to hold talks with Angolan President Jose Eduardo dos Santos before leaving for the Democratic Republic of Congo.

Mrs Clinton travelled to Angola from South Africa, where she held talks with President Jacob Zuma in Durban.