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

Peru's left-wing President-elect Pedro Castillo revealed on Tuesday he would be looking to form a pluralistic government in his first remarks to reporters since his election was confirmed.

The trade unionist's victory over right-wing populist Keiko Fujimori was confirmed on Monday, more than six weeks after the second-round presidential run-off.

Castillo beat Fujimori by just 44,000 votes on Monday night. 

"We're forming a working team and I can see that there are people who are pretty interested in supporting this government, from all political persuasions, also people who aren't political that I met today and who are available," said Castillo, who will be inaugurated next week.

"We are putting out a call to all the experts, to the most distinguished and committed people in the country," added the rural school teacher as he left a government building in central Lima. 

Castillo's victory was delayed due to a jury review of claims of electoral fraud made by Fujimori, despite observers from the Organization of American States, the European Union and US declaring the vote free and fair.

Governability will be one of Castillo's great challenges following a polarized campaign in which his opponent repeatedly branded him a communist and tried to discredit him.

"I ask for calm and serenity from the Peruvian people. That's not just the government's responsibility but also that of all Peruvians," said Castillo, 51. 

He must soon announce his cabinet and appointments to key ministries.

But his Peru Libre (Free Peru) party holds only 37 of the 130 seats in a fragmented congress meaning he faces a challenge in delivering on the promises he made during the campaign, in a country that has been rocked by recent political upheaval that saw three different presidents in power in November 2020 alone.

However, he received a boost from the major business organization Confiep, which said it was "available for constructive dialogue to achieve inclusive growth for everyone."