Ambronicus Nababan, who is chair of the Pro Jokowi-Amin Volunteers (Projamin), made the racial remark about Natalius Pigai, a Papuan who is a former chairman of Indonesia's National Human Rights Commission.
The "monkey" epithet is the same slur that triggered mass anti-racism protests across Papua region in 2019.
The Liberation Movement's leader Benny Wenda said that since Indonesian troops invaded Papua in 1963, Jakarta's elites had made clear their racist plans to destroy Melanesian West Papuans as a distinct people.
In response to Hendropriyono's remarks, Wenda noted it as a viewpoint with currency among elements of Indonesia's leadership.
"This is racial ethnic cleansing, a genocidal fantasy at the highest levels of the Indonesian state," Wenda said.
He said the remarks stood in a long tradition.
The West Papuan independence campaigner Benny Wenda. Photo: RNZ / Jamie Tahana
"When Indonesia invaded our land, General Ali Moertopo said the Papuan people should be transferred to the moon," Wenda said in the statement.
Wenda said racism has been at the heart of Indonesia's settler colonial project in West Papua.
He said this was why the Liberation Movement established a provisional government for a prospective independent West Papua in December last year. Wenda is its interim president.
"My people rose up against this racism and colonisation in 2019. Thousands of students returned from the rest of Indonesia in an exodus from racism, dozens were killed by Indonesia, and hundreds arrested.
"The Indonesian state punished those who spoke out with over 100 years of collective prison time. The killers and racists in the army, police and state-backed militias were allowed to go free."