Dozens of African leaders have assembled in Washington for a summit aimed at rebooting US relations on the continent, which have languished in recent years.

The US-Africa summit, the first since 2014, will be the biggest international gathering in Washington since the pandemic and the most substantial commitment by a US administration to boosting its influence in the region for almost a decade.

The summit comes amid the sharpest great power rivalry for many decades, worsening security problems and acute economic problems in Africa.

All three challenges are sometimes blamed on the US, which has been pushed on to the defensive in many areas by determined and often unconventional strategies adopted by strategic rivals such as Russia and China.

In all, 49 leaders and heads of states have been invited to the summit, and the guest list underlines the difficulty faced by President Joe Biden and the secretary of state, Antony Blinken, in balancing values with pressing demands of power politics.

Observers have noted tensions in US policy between a desire to win friends and also to reach out to populations suffering under repressive, exploitative regimes through promotion of diversity, tolerance, free speech and democracy.

“It seems it’s now a numbers game and getting more countries to align with the west against Russia now and, in the longer term, China. The continent feels a lot more cold war-ish than at any time in my career,” said Alex Vines, director of the Africa programme at Chatham House.

Four countries that were suspended from the African Union – Burkina Faso, Guinea, Mali and Sudan – were not invited to the summit because coups in those nations led to unconstitutional changes in power. The White House also did not invite Eritrea.

But Equatorial Guinea was invited despite the state department stating that it held “serious doubts” about last month’s election, in which President Teodoro Obiang’s ruling party won nearly 95% of the vote.

So too was Zimbabwe, which has faced years of US and western sanctions over poor governance, human rights abuses and widespread corruption, and Ethiopia, some of whose commercial privileges were withdrawn in an attempt to force an end to a war in the Tigray region that led to “gross violations” of human rights.

A peace deal was signed last month, with the significant involvement of US diplomats, but implementation faces major challenges.

Many African leaders have come with their own agendas, such as seeking help with high debt repayments, the devastating legacy of the coronavirus, climate change, or military assistance. Most countries are suffering too from the impact of Russia’s invasion of Ukraine, which has pushed up inflation and disrupted food supplies.

Geopolitical competition goes beyond that between China, Russia, the EU and the US to include middling powers such as Turkey, Japan, the Gulf states and the UK too, said Vines.

On a tour of three countries in Africa earlier this year, Blinken appealed to “governments, communities and peoples” across Africa to embrace Washington’s vision of democracy, openness and economic partnership.

The US diplomatic strategy appears in part to appeal directly to ordinary people in Africa, rather than their leaders, by promising support for democracy and accountability. Few rulers on the continent welcome Washington’s admonishments about their often poor human rights records or failures to implement political reform.

“I do strongly believe that the United States is still seen as a superpower from the African perspective, but most African leaders do not want to align with its promotion of democracy,” said Abraham Kuol Nyuon, a political analyst and associate professor of political science at the University of Juba in South Sudan. “They need the support of America but not the system of America.”

China has made little secret of its preference for strongman rulers, offering assistance without conditions. Sub-Saharan nations have also been major recipients of Chinese investment through its now flagging “belt and road initiative”, which supported infrastructure development.

The Russian strategy has been more opportunistic, and has been focused on unstable countries with significant resources such as Sudan or those where once pro-western political leaders are now seeking new allies.

On his tour, Blinken sought to counter Russian and Chinese accusations that the US is a “neo-imperialist power” by stressing that Washington wants to act in consultation with local leaders and communities, reinforcing existing African initiatives.

“The United States prioritises our relationship with Africa for the sake of our mutual interests and our partnership in dealing with global challenges,” said Molly Phee, an assistant secretary of state for African affairs. “We are very conscious, again, of the cold war history, we’re conscious, again, of the deleterious impact of colonialism on Africa, and we studiously seek to avoid repeating some of the mistakes of those earlier eras.”

A further aim is to make sure failures of Trump’s administration – marked by drift and a series of insulting gaffes – are forgotten.

African leaders will be looking for Biden to make some big commitments during the summit, including announcing his first presidential visit to sub-Saharan Africa. One crowdpleaser may be support for adding the African Union as a permanent member of the G20, according to the White House.

The Senegalese president, Macky Sall, the current AU chair, has argued that by adding the African Union, the G20 “would come to represent the views of 54 additional members, the bulk of low-income countries, and about 80% of the world’s population”.

He wrote in July: “The G20 compromises its effectiveness and influence by omitting such a large fraction of humanity and the world economy.”