There is growing uncertainty over the fate of hundreds of migrants and refugees as a rescue ship remained stranded at sea for a fifth day after both Italy and Malta refused to give it docking approval.

Lifeline, a ship belonging to a German NGO of the same name, remained stuck on Maltese waters on Monday with 234 Africans onboard, who were rescued in the Mediterannean on Wednesday. Among them are four children younger than three.

Italy's far-right Interior Minister Matteo Salvini said on Monday that the vessel, which is moored about 30 nautical miles (56 kilometres) off Malta, will not be allowed to dock in Italy.

Salvini had bluntly told foreign charities on Sunday to stop rescuing migrants and refugees off Libya, where one group said 1,000 people were on boats in distress.

"The Italians told us the responsibility is on the Libyans," Claus-Peter Reisch, Lifeline captain, told The Associated Press news agency. "And the Libyans, if you try to call them, they don't pick up the phone."

The mayor of the Spanish city of Barcelona has offered his help but the harbour cannot be reached because of bad weather and distance, according to Lifeline spokesman Ruben Neugebauer.

At the moment, the ship carries enough food and water for all passengers on board.

Lifeline’s co-founder Axel Steier told AFP news agency that the Dutch-registered vessel was turned away by the Italian authorities and told to go to Libya.

An email sent by Lifeline to the Libyan coastguard remains unanswered, according to Steier.

Lifeline on Monday asked for permission to berth in France.

"The problem is that we have 234 people on a 30-metre-long boat near a developed country and Europe is watching these people slowly waste away,” Steier said.

Separately, Italian news agency Ansa quoted Steier telling France’s RTL radio that the rescued ship had been "refused by Germany, Holland and Italy”.

"Today we’ll ask France to receive us. If we don’t get a response, we’ll head north, to Spain or France”.

As the people on board await their fate, European Union (EU) members struggled to find a solution to the migration crisis at emergency talks in Brussels on Sunday.

To discuss the issue, Salvini, who is also one of Italy’s two deputy prime ministers, also held meetings with Libyan officials, including Interior Minister Abdelsalam Ashour in Libya’s capital, Tripoli, on Monday. Agencies