Peace, security, democracy and the youth question will be key issues to be discussed when US President Barack Obama hosts African heads of state later this year, a US top diplomat revealed on Tuesday.

But the Assistant Secretary of State for African Affairs, Ms Linda Thomas-Greenfield, said the exact agenda will be released after discussions with African experts.

"We are in consultation with experts on the African continent to determine what issues they are interested in discussing during the Summit," she told journalists via video conference.

"We have had a number of issues come forward. Peace and security is high on the agenda and it is locally considered (by the US) as one of the issues that we intend to have on the agenda.

The diplomat argued the continent's youthful population has caused excitement but there was a need to address the "bulging" youth numbers.

READ: Africa's youthful populace key resource for economic growth

Forty-seven leaders, mostly from sub-Sahara Africa, including Kenya's President Uhuru Kenyatta have been invited to attend a conference on US-Africa relations in Washington in August.

The leaders are also expected to discuss the extension of the AGOA treaty; which provides for easier ways for Africa to export products to the US.

Ms Thomas-Greenfield said the US expects to extend it by the end of next year.

The conference is seen as the US' move to counter China's growing influence on the continent. The Far East country has been hosting a similar summit under the mantle of Focus on China-Africa Cooperation (FOCAC).

And although the sudden turn to the East by African leaders is thought to result from China's non interference, the US insists it will not patronise Africa on democracy and good governance.

"We still believe countries should be transparent. We are not changing our stand just because it is giving an unfair advantage to Chinese companies."

"We always want a level-playing field but those Chinese companies will just realise that it is important to operate in a transparent environment."