Supporters of leftist schoolteacher Pedro Castillo celebrate in downtown Lima following the official proclamation of him as Peru's president-elect on Monday. Photo: AFP

Leftist Pedro Castillo is to be sworn in as Peru's president Wednesday with a full inbox: tame the coronavirus epidemic, reactivate a flagging economy, and put paid to years of political turmoil.

The rural school teacher becomes Peru's fifth president in three years, and has vowed to upend a quarter century of neo-liberal government.

He was declared the victor on July 19, more than six weeks after a runoff vote against rightwing rival Keiko Fujimori, whose fraud claims were then reviewed by an electoral jury.

Three days of ceremony are planned, starting with the swearing-in Wednesday on Peru's independence day - an event that will be attended by Spanish King Felipe VI, six Latin American leaders, former Bolivian President Evo Morales, and the US education secretary among the guests.

A military parade is planned for Lima on Friday. Castillo, 51, becomes Peru's first president in decades with no ties to the country's political or economic elite.

He has promised reform to ensure there are "No more poor people in a rich country," but has softened his initial campaign talk of nationalization.

Castillo's Free Peru party does not enjoy a majority in a fragmented congress, holding 37 of the 130 seats. Fujimori's Popular Force party has 24.

The country has been hard hit by the coronavirus epidemic. With nearly 200,000 deaths among its 32 million population, it has the world's highest reported mortality rate.

An extended pandemic lockdown in 2020 is blamed for the loss of millions of jobs and dumping the country into recession. GDP dropped more than 11 percent.

As his chief economic adviser, Castillo has appointed World Bank economist Pedro Francke, seen as a moderating influence on his boss, who had initially said Peru's mining and hydrocarbon riches - a mainstay of the economy - "must be nationalized."

Francke vowed, in an interview with AFP, that "we will not expropriate, we will not nationalize, we will not impose generalized price controls, we will not make any exchange control that prevents you from buying and selling dollars or taking dollars out of the country."