Amnesty International urged the European Union on Friday to suspend plans on returning asylum seekers to Turkey, ABC News reports.
The rights group released a 35-page briefing deeming the EU-Turkey deal to tackle irregular migration was "illegal" and "reckless."
Turkey is hosting 3 million refugees, including 2.75 million Syrians, and under the agreement with Brussels, the country is expected to receive more.
Under the accord, irregular migrants who arrived to the Greek islands from Turkey after March 20 will be sent back to Turkey.
The EU, in turn, will resettle one Syrian refugee from Turkey to one of the bloc's member states each Syrian that Greece sends back to Turkey.
Turkey also stands to receive up to EUR 6 billion, visa-free travel and speed up negotiations on EU accession.
Amnesty International deems the deal unlawful because asylum seekers do not access "effective protection" in Turkey. The group argued that Turkey lacks the capacity to process asylum applications and falls short on key criteria to be deemed a "safe third country."
"In its relentless efforts to prevent irregular migrants to Europe, the EU has willfully misrepresented what is actually happening on the ground in Turkey," said John Dalhuisen, Amnesty's director for Europe and Central Asia.
Turkey, it noted, does not accord full refugee status, and most refugees in the country do not obtain government support.
The organization also repeated its assertion that Syrians in Turkey are at risk of being forcibly sent back to their war-torn nation.
Turkish officials have rejected prior Amnesty International reports on the issue of forced returns.