“I would like to ask for understanding from the people as I announce that I will not continue as prime minister,” he said in a special broadcast on state television, according to the news site.
“[My son] Hun Manet … will become the prime minister in the coming weeks,” he said, adding that the new leader will be appointed on August 10. “I will continue as the head of the ruling party and member of the National Assembly,” he said.
Hun Sen's party, the Cambodian People’s Party (CPP) won 82 per cent of the vote at last week's general elections. The turnout was 84.6 per cent.
According to SCMP, Hun Sen has trailed the handover to his son for a year and a half, and the 45-year-old played a leading role in campaigning for Sunday’s vote.
Under Hun Sen, Cambodia has tacked close to Beijing, benefiting from huge Chinese investment and infrastructure projects, including the redevelopment of a naval base that has alarmed Washington, SCMP wrote, adding that China welcomed Sunday’s election, with President Xi Jinping sending Hun Sen a personal message of congratulation.