Philippine President Rodrigo Duterte said on Tuesday that he might not "be around" until the end of his term, and that, after winning the presidency at 71, he had found out late in the day that "I don't need it at my age."

The previous day he had told a gathering of business leaders in the Philippines that he suffered from back pains, migraines and Buerger's disease, a cause of blockages in the blood vessels, associated with smoking during his youth.

On Tuesday, Duterte told a cheering crowd of a few thousand expatriate Filipinos in the Cambodian capital Phnom Penh: "I am old ... This is my last hurrah — after this, 77 — I am not sure if I will still be around by the end of my term."