Zimbabwe President Robert Mugabe has made his first public appearance this year, quashing speculation about his health as he mourns his sister's death.

State television on Monday showed images of Mugabe greeting government officials and members of his ZANU-PF party at his official residence in the capital Harare.

The veteran leader, who turns 90 next month, did not show signs of declining health as he greeted those paying their condolences at State House on Sunday, after his younger sister Bridget passed away in a Harare hospital.

His appearance quashed recent speculation about his health, with some media even claiming he died while on holiday in Singapore.

Presidential George Charamba last week dismissed the reports, saying the long-time president, in power for 33 years, was on his annual leave and in good health.

Mugabe takes a month-long-holiday each January, and has made several stays in southeast Asian countries.

Government sources said he cut this year's vacation short due to his sister's deteriorating health.

He was reportedly seen visiting her in hospital early last week.

The 78-year-old Bridget died after a three-year coma. She collapsed at the burial of another sister in 2010.

The eldest of his siblings, Mugabe now has only one living younger sister.

Mugabe's health has been the subject of speculation in recent years, with some media suggesting he sought medical treatment in countries including Malaysia and Singapore.

A US diplomatic cable from 2008, leaked two years ago by anti-secrecy website WikiLeaks, quoted Mugabe's close ally and former central bank chief Gideon Gono as telling former US ambassador Christopher Dell that Mugabe had been diagnosed with prostate cancer.