LAMPEDUSA, Italy — The stand-off between a Sea-Watch rescue boat and Rome escalated on Thursday as the European Commission called for relief for 42 migrants stranded on the spurned vessel.

"We waited one night. We cannot wait another," the German NGO tweeted on Thursday, a day after the Sea-Watch 3 entered Italian waters despite the threat of a hefty fine.

"Desperation of people in need is nothing to gamble with."

The Sea-Watch 3 entered Italian waters on Wednesday despite a threat of hefty fines from far-right Interior Minister Matteo Salvini. It is waiting off the coast of Lampedusa island.

The ship's Captain Carola Rackete has said she is ready to go to prison to bring the migrants to safety. They have spent more than two weeks at sea.

Salvini has said the migrants can only disembark if they head straight to the Netherlands, where the Sea-Watch 3 is registered, or to Germany.

The anti-immigrant Lega leader accuses NGOs of aiding human trafficking and says Europe should better share the load of receiving migrants.

EU Migration Commissioner Dimitris Avramopoulos said Brussels was "closely involved in coordinating with the member states to find a solution for relocating the migrants on board Sea-Watch 3 once they are disembarked."

"A solution for people on board is only possible once they are disembarked," Avramopoulos said in a statement. "I hope that Italy in this particular incident will contribute to a swift resolution for the persons on board."

Commission spokeswoman Natasha Bertaud noted that while "the duty to rescue is clear", "there is no obligation for countries to accept disembarkation for incidents from outside their rescue area."

Of the 53 migrants initially rescued by the Sea-Watch 3 off Libya on June 12, Italy has already taken in 11 vulnerable people.

Aid groups and the UN say it is not safe to take migrants back to war-torn Libya.

Salvini has tried to ban the Dutch-flagged vessel from approaching under a "closed ports" policy which has seen migrants repeatedly stranded at sea.

"I hope that in the coming hours there will be a judge to say that there are outlaws on board this vessel," Salvini told Italian radio on Thursday.

Salvini has threatened to not register the migrants on arrival and to send them on elsewhere in Europe, but Brussels has warned this would result in a penalty procedure for Rome.

On Wednesday, the interior minister said Rome's ambassador to The Hague was "taking a formal step with the Netherlands government" to resolve the issue.

Salvini this month issued a decree that would bring fines of up to 50,000 euros ($57,000) for the captain, owner and operator of a vessel "entering Italian territorial waters without authorization".

A Facebook fund to pay for Sea-Watch's legal fees and fines collected at least 135,000 euros on Thursday, a day after it was set up.

Italy's interior ministry says nearly 500 migrants have arrived in the country over the last two weeks aboard smaller vessels while the Sea-Watch 3 has zigzagged on the high seas without a safe port.

A small boat carrying 10 migrants, reportedly from Tunisia, sailed past the Sea-Watch 3 at dawn on Thursday and landed them in italy.

Italian police on Wednesday evening intercepted a boat carrying another 34 migrants and took them to Sicily.

In January, 32 migrants rescued by the Sea-Watch 3 were stranded on board for 18 days before they were allowed to disembark in Malta following a distribution deal agreed by several European countries, including the Netherlands.

"It's serious when the captain has no other choice but to honor her sense of responsibility at the cost of personal consequences," said Carlotta Sami, spokeswoman for the UN refugee agency in Italy, adding the "criminalization of NGOs must end".

Meanwhile, Spanish rescue vessel Open Arms headed back to the waters of Libya on Thursday despite the threat of a 200,000-900,000 euro fine from the Spanish authorities.

"Our mandate is to rescue people, we're going there to witness and do what we can so that no lives are lost," Proactiva Open Arms spokeswoman Laura Lanuza said. — AFP