HANOI (AFP) - General Le Duc Anh, a Communist Party hardliner and former Vietnamese president who led the invasion of Cambodia which led to the fall of the Khmer Rouge regime, has died aged 99.

Duc Anh, who was born in 1920, spent much of his life in southern Vietnam, where he joined the communist war effort against the French and then the United States.

Duc Anh died late on Monday (April 22) "following a long illness", the government and state media announced.

He served as president between 1992-1997, championing the continued primacy of the Communist party as Vietnam embarked on sweeping market reforms that spurred remarkable economic growth.

In 1995, he became the first Vietnamese head of state to set foot on US soil after the Vietnam War when he attended the 50th anniversary of the United Nations in New York.

Educated in the former Soviet Union and blind in one eye, he held various military posts during the Vietnam War.

He was one of the "liberators of Saigon" as deputy commander of the offensive that toppled the US-backed South Vietnamese government.

He is best remembered for playing a commanding role in the invasion of Cambodia that drove Pol Pot's Khmer Rouge out of Phnom Penh in 1978, earning him the nickname "Tiger of Cambodia".

"At the time, the Khmer Rouge had plans to fight their way to Saigon," he told Vietnamese media in 2009.

"Without our support... how would the Cambodians have risen up to liberate their own country?" he added.

A state funeral is expected to be held for him.