The group will give evidence on Monday to the United Nations Committee's working group on minorities about the threat to Welsh-speaking communities in rural areas.
The UN committee - which reports back to the Commission on Human Rights - aims to promote and protect the rights of groups belonging to linguistic and ethnic minorities.
It is understood to be the first occasion evidence has been taken from Wales.
Cymuned has been given 15 minutes to present its concerns about the future of Welsh-speaking areas and will be represented by Dr Jerry Hunter and Judith Humphreys.
Ahead of the trip, Dr Hunter said: "This is the first time ever a Welsh organisation has been given official accreditation to present evidence to the United Nations.
"Cymuned has now been recognised by the United Nations on the international stage."
He added: "Welsh-speaking communities are a minority community, and as a minority community, they have rights under international law."
Cymuned was formed last year in the wake of controversial comments by Gwynedd Councillor Seimon Glyn about English incomers being a "drain on Welsh-speaking communities".
His comments rekindled the debate of the language issue and led to a series of high profile Welsh speakers adding to calls for Welsh Assembly suport for rural communities.
Cymuned has attracted support from disaffected Plaid Cymru members, academics and professionals.
Among several proposals was a bid to aid Welsh speakers by placing restrictions on outsiders owning second homes.
In February, Cymuned member Simon Brooks warned "civil disobedience" was inevitable unless the assembly's review of the language delivered acceptable solutions.
TV licence refusal
Welsh Language Board Chairman Rhodri Williams, said the threats were a mistake and that people should make their feelings known through the ballot box.
In the past, Welsh activists have occupied public buildings, sprayed slogans, climbed television masts and refused to pay TV licence fees.
A BBC Wales poll earlier this year revealed one third of Welsh-speaking parents never use the language when talking to their children.
The survey also revealed that just four in 10 mothers and fathers who speak Welsh routinely use the language within their family.
The survey, conducted by Beaufort research for BBC Wales, also found resistance to Welsh as a compulsory subject in secondary schools.
In addition, 60% of the 1,004 people interviewed believe monoglot English-speaking incomers to Welsh heartlands make an economic contribution to their communities.