Leader of the United Liberation Movement for West Papua Benny Wenda called for ordinary Indonesians to be "the voice of the voiceless" as he urged vigilance in the continued struggle for independence.
He hailed success in the recent trial of political prisoners who could be freed within weeks after being sentenced to 11 months instead of the 17 years demanded by prosecutors.
"This is a great victory for our movement worldwide. Although it is still an outrage that victims of racism have been found guilty of 'treason' for alleged involvement in anti-racist demonstrations, it could have much worse.
"The worldwide pressure, from civil societies to legislatures, made all the difference," Mr Wenda said.
He warned of a possible appeal by prosecutors, insisting that pressure is needed "to ensure total freedom for the political prisoners."
Buchtar Tabuni, a leading figure in the ULMWP and Irwanus Uropmabin and Ferry Gombo, university students in Jayapura, were sentenced on Monday for their part in last year's West Papuan uprising.
At least 30 people were killed in violent clashes and hundreds of West Papuans were taken into custody.
The trio were charged with treason for demanding a referendum on independence for West Papua during speeches in Jayapura.
"We need ordinary Indonesians to be the voice of voiceless West Papuans. We need you to show the same support for Papuan Lives Matter as you do for Black Lives Matter.
"We need your help to achieve the total liberation of the people of West Papua. With your assistance, one day you will be proud that West Papua is free, and we will live peacefully, side by side, as good neighbours," he appealed.
Indonesia annexed West Papua, formerly a Dutch colony, via a "fake referendum" in 1969 in which a handpicked group of 1,022 Papuans were coerced into ratifying Indonesian occupation through the so-called Act of Free Choice.