A weary President Robert Mugabe, 91, reportedly showed signs of fatigue during celebrations to mark the country's Defence Forces Day on Tuesday.

It was said the veteran leader struggled to walk to the podium where he delivered his speech in less than 30 minutes.

This was after standing for a few minutes during an inspection of the military parade, the report said.

The nonagenarian chose to stick to his prepared speech on the operations of the Zimbabwe Defence Forces (ZDF).

Mugabe is generally known for using such occasions to vent his anger at the West, which he blames for the continued deterioration of his country's economy.

The European Union (EU) imposed sanctions against Zimbabwe in 2002 over electoral fraud and human rights abuses.

Mugabe's brief address was in sharp contrast to the speech delivered at the Heroes Acre the previous day, which lasted over an hour, the report said.

Mugabe, who has been in power since Zimbabwe's independence in 1980, insists that he is healthy.

His ruling Zanu-PF party has already endorsed him to stand in the 2018 presidential elections.

Mugabe, according to the state-owned Zimbabwe Broadcasting Corporation (ZBC), commended the ZDF for its role in "being a formidable force that safeguards the country's territorial integrity, sovereignty, social and economic development".

Mugabe also said the ZDF continued to do the nation proud through numerous operations.

"Recently, the ZDF were successful when deployed in Lesotho as an observer mission following disturbances in the mountain kingdom," Mugabe was quoted as saying.