Vanuatu, Solomon Islands, Tonga, Tuvalu, Nauru, Palau and the Marshall Islands delivered a joint statement at the ACP's Council of Ministers in Brussels.
It condemned Indonesian human rights violations in Papua, including alleged crimes against humanity and called for an eventual resolution that includes support of the right of West Papuan political self-determination.
Delivering the statement, a Vanuatu government envoy Johnny Koanapo told the Council that "apartheid-like colonial rule" was "slowly but surely" going to wipe out West Papuans as a people "while… the world stood by."
African and Caribbean countries in the the 79-member group of mainly former colonised territories have voiced strong support for West Papuan self-determination at subcommittee and ambassadorial level during the past two months
Mr Koanapo said that the day's discussion "now sets up the great likelihood of a resolution on the full range of West Papua issues at the next ACP ministerial council meeting", scheduled for November.
It's the latest in a string of high-level representations by the International Coalition for Papua since last year that have taken the issue of West Papua to a new level of diplomatic activity.
The seven Pacific nations, who are in coalition with Pacific regional church bodies and civil society networks, raised concern about West Papuan human rights at the UN Human Rights Council in Geneva two months ago, and also at the UN General Assembly last September.
Indonesia's government has rejected criticism at the UN level, accusing the Pacific countries of interference and supporting Papuan separatism.
Jakarta says human rights abuses in Papua are largely historical, and that the incorporation of the western half of new Guinea into Indonesia is final.
However, support from other governments for resolution of ongoing human rights infringements in Papua is gaining momentum.
Criticism of the flawed plebiscite by which the former Dutch New Guinea was incorporated into the young state of Indonesia in the 1960s has effected renewed calls for a genuine self-determination process.
At yesterday's Brussels meeting Papua New Guinea's ambassador, whose country shares a 760km-long border with Indonesia at West Papua, was the only delegate to speak against ACP moving forward on a resolution on the matter.
Joshua Kalinoe said that "no one is denying that the human rights violations are going on" but suggested that a fact-finding mission to West Papua might be necessary for the ACP to get an accurate picture of the situation.
Guinea-Bissau's Ambassador Alfredo Lopez Cabral spoke next, comparing the plight of West Papua to East Timor, which Indonesia occupied for 24 years before a mounting legacy of conflict gave way to an independence referendum in 1999.