US President Joe Biden has announced billions of dollars in support and investment for Africa at a summit with the continent's heads of state.

"The United States is all in on Africa's future," President Biden told the 49 African leaders attending the Washington DC meeting.

It is the first such gathering hosted by Washington for eight years.

The summit is seen as a US attempt to re-assert its influence in Africa to counter Chinese involvement.

It also comes after Donald Trump's four-year tenure in office, during which he alienated numerous African leaders with policy decisions and insulting comments.

Mr Biden struck a very different tone to his predecessor, speaking optimistically of improved links with Africa and telling the gathering that "when Africa succeeds, the United States succeeds. Quite frankly, the whole world succeeds as well."

To that end, ahead of the three-day summit which ends on Thursday, National Security Advisor Jake Sullivan said the US would commit $55bn (£44bn) to Africa over the next three years.

Discussions at the summit have focussed on building on already existing programmes, including:

But the success of such programmes has been slow to realise. Africa only accounts for just over 1% of US foreign trade, which is dominated by petroleum imports from Nigeria and Angola.

In his address on Wednesday, the US president spoke about a $500m-investment to reduce transport costs at a key West African port in Benin.

He also mentioned $350m that would be spent on boosting the digital economy and said that $15bn-worth of deals had been struck at the US-Africa Business Forum.

The US is also set to sign a memorandum with the African Continental Free Trade Area - one of the world's biggest free-trade areas - which Mr Biden said would "unlock new opportunities for trade and investment" between the US and Africa.

On the sidelines of the summit on Wednesday, Mr Biden separately met the six leaders of African nations which are holding elections in 2023 to press for free votes.

On Thursday, the US president said he would back the African Union's admission as a permanent member of the Group of 20 major economies.

Analysis by Barbara Plett Usher, BBC State Department correspondent

This was about President Biden trying to win back influence in Africa with personal diplomacy as well as by promising billions of dollars of funding in key sectors and rallying private sector investments.

The subtext was that America was trying to catch up with other countries, including Russia and especially China, that have developed stronger ties with the continent.

But the message was that the US wanted a strategic relationship with Africa, which has become a key geopolitical player with some of the fastest growing economies in the world.

The summit will have been successful for the Americans if they can demonstrate that Africa is more than a battleground for competition with Beijing and Moscow. They want to show that they can be better partners than China or Russia.

But following up and sustaining engagement will be crucial to proving US commitment and for that the White House appointed a special envoy.