Human Rights Watch (HRW) has said Bangladesh and Myanmar should invite UNHCR to join in the drafting of a new tripartite agreement.
Frelick said a central role for the UNHCR, the only UN agency with a statutory mandate to facilitate the voluntary repatriation of refugees.
He also termed Rohingya return deal bad one
"After the widespread violence, safe and voluntary return of Rohingyas will require international monitors on the ground in Burma," said Bill Frelick, refugee rights director at HRW.
Headquartered in New York, HRW is aninternational non-governmental organization that conducts research and advocacy on human rights.
The current agreement also commits Myanmar "to see that the returnees will not be settled in temporary places for a long time."
"This should include some existing provisions, such as encouraging refugees to return voluntarily and safely to their own households and original places of residence or to a safe and secure place nearest to it or their choice," the global watchdog body said given the "critical flaws" in the agreement.
The agreement by Bangladesh and Myanmar to begin returning Rohingyas to Myanmar by January 23, 2018, creates an "impossible timetable" for safe and voluntary returns and should be shelved, HRW said in a letter to the two governments.
International donors, who would be needed to fund the massive repatriation effort, should insist that Bangladesh and Myanmar invite the United Nations High Commissioner for Refugees (UNHCR) to join in drafting a new tripartite agreement that ensures adherence to international standards, it said.
Since late August 25, more than 645,000 ethnic Rohingyas have fled a campaign of ethnic cleansing by Myanmar's security forces and sought asylum in Bangladesh.
Human Rights Watch has interviewed more than 200 of the refugees. Many said that they wish to eventually return home, but that they do not believe it is safe to return to Burma for the foreseeable future and until their security, land, and livelihoods can be ensured, says a UNB report.
"Burma has yet to end its military abuses against the Rohingya, let alone create conditions that would allow them to return home safely," said Frelick.
"This agreement looks more like a public relations effort by Burma to quickly close this ugly chapter than a serious effort to restore the rights of Rohingya and allow them to voluntarily return in safety and dignity."
On November 23, Bangladesh and Myanmar signed an "Arrangement on Return of Displaced Persons from Rakhine State" on behalf of "residents of Rakhine State" who crossed from Burma into Bangladesh after October 9, 2016 and August 25, 2017.
The agreement makes no reference to the cause of most of the forced displacement: a campaign of killings, widespread rape, and mass arson carried out by Burmese security forces that amounted to crimes against humanity.
The HRW said the agreement also fails to identify the displaced either as Rohingya or as refugees.
It said voluntary repatriation in safety and dignity as required by international law will not be feasible until the Myanmar government demonstrates its willingness and ability to ensure full respect for returnees' human rights, equal access to nationality, and security.
The agreement expresses Myanmar's commitment to "take necessary measures to halt the outflow of Myanmar residents to Bangladesh" - which raises grave concerns since everyone has a right to flee persecution in their own country.
The agreement also makes no direct reference to non-refoulement, the principle of international refugee law that prohibits the forcible return of refugees to places where their lives or freedom would be threatened.
And the agreement restricts returnees' freedom of movement to Rakhine State in "conformity with existing laws and regulations," many of which discriminate against the Rohingya.
Several Burmese officials have spoken about putting Rohingya in "camps." This would be an unacceptable approach to their return as camps set up after previous anti-Rohingya violence have led to de facto detention and segregation.
While the agreement says that Bangladesh will immediately seek assistance from UNHCR to carry out safe and voluntary returns, Myanmar agrees only "that the services of the UNHCR could be drawn upon as needed and at the appropriate time."