The captain of the Sea-Watch 3 charity rescue vessel threatened Tuesday to enter Italian waters illegally to bring 42 migrants to shore after they spent 13 days in limbo at sea.
Interior Minister Matteo Salvini has banned the Dutch-flagged vessel from approaching under a "closed ports" policy, which has seen migrants repeatedly stranded at sea.
"I will enter Italian waters and bring them to safety on Lampedusa," Carola Rackete said in an interview with La Repubblica daily, in reference to Italy's southernmost island.
The European Court of Human Rights (ECHR) in Strasbourg on Tuesday declined to intervene but called on Italy to "continue to provide all necessary assistance" to vulnerable migrants.
The German NGO Sea-Watch had asked the ECHR to impose "interim measures" on Italy, saying the court could ask Rome to take urgent steps to resolve the standoff in order to "prevent serious and irremediable violations of human rights".
Salvini said Tuesday the charity vessel could "stay there until Christmas and New Year" but would never be allowed in.
Of the 53 migrants initially rescued by the Sea-Watch 3 off Libya on June 12, Italy took in 11 vulnerable people.
"That's enough! Whatever Strasbourg tells us, with great serenity we will maintain our position," Salvini said.
"Imagine if a country like Italy - the second-largest industrial power in Europe - let an NGO dictate immigration rules," he said.
On Lampedusa, where Salvini's far-right League won 45% in May's European elections, a priest has camped in the street to demand those on board - including three minors - be allowed to disembark.
Dozens of German cities have said they are ready to welcome them, and the Bishop of Turin, Cesare Noviglia, said Monday his diocese would be willing to take them in.
"We can't hold on any longer. It's like we're in a prison because we are deprived of everything. Help us, think of us," one migrant from the Ivory Coast said in a video broadcast by Sea-Watch.
In January, 32 migrants rescued by the vessel were stranded on board for 18 days before they were allowed to disembark in Malta thanks to a distribution deal made between several European countries.