The European Commission on Wednesday called for the "immediate disembarkation" at the "nearest place of safety" of the people onboard the Ocean Viking rescue vessel.
This is an unusual move for the European Union's executive as immigration decisions are a national issue.
The European Commission said in a statement that the "situation onboard the vessel has reached a critical level and needs to be urgently addressed to avoid a humanitarian tragedy."
"The legal obligation to rescue and to ensure the safety of life at sea is clear and unequivocal, irrespective of the circumstances that lead people to be in a situation of distress," it added.
The Ocean Viking ship, operated by the SOS Mediterranee, has 234 people on board, including over 40 unaccompanied minors and four children under the age of 4. Some of them have been stranded on the vessel for 19 days.
The ship is currently located near the Italian island of Sardinia, according to the MarineTraffic.com website.
The SOS Mediterranee said on Tuesday that it had sent a Place of Safety request to French authorities and that it expected to arrive in international waters close to Corsica on 10 November.
The ship demanded authorisation to dock at an Italian port daily since 27 October but was repeatedly denied.
It then started sending daily requests to French, Spanish and Greek authorities from 2 November to similar results.
"The situation onboard Ocean Viking reached a critical limit. We are facing very severe consequences, including risks of loss of lives," Xavier Lauth, SOS Mediterranee's Director of operations, said in a statement on Tuesday.
"Physical and psychological well-being of survivors and crew have been exhausted by over two weeks of blockage at sea."
The ship's Search and Rescue coordinator, Nicola Stalla, meanwhile said that "in the past days, maritime and humanitarian laws were blatantly violated in Sicily, with the implementation of selective and discriminatory disembarkation processes of people rescued by the NGO vessels Humanity 1 and Geo Barents."
Italian government reminded of 'principle of sincere cooperation'
Italy's new right-wing government cleared the Humanity 1 and Geo Barents vessels, respectively operated by SOS Humanity and Médécins Sans Frontières (MSF), to temporarily dock in Sicily on 5 and 6 November.
However, Rome only allowed a total of 600 people to disembark following "vulnerability" assessments by two doctors selected by the authorities.
The Commission added in its statement that it "recalls the principle of sincere cooperation and calls on Member States to work together to ensure a common response, with the sanctity of life being of utmost importance and primary consideration."
It also called for more support for "those member states regularly receiving arrivals by sea", including through the Solidarity Mechanism.
The Commission's call came just an hour after the United Nations High Commissioner for Human Rights told Italy and the EU that "politics mustn't be done at expense of people in distress".
"Migrants need our wholehearted support — humanity demands it. Human rights must be at core of search and rescue efforts. Timely disembarkation in a safe place for those rescued at sea is crucial," Volker Türk added.
The EU's executive unveiled its proposal for a New Pact on Migration and Asylum in 2020 that planned for a predictable and reliable migration management system.
It also calls for more stringent contributions from member states in terms of relocations or support in other forms, such as financial assistance.
But member states disagree on a wide array of issues, including whether the contributions should be binding.
At least 1,337 people have gone missing on the Central Mediterranean migration route this year, according to Missing Migrants Project, an initiative implemented by the International Organisation for Migration, or IOM.