Italy has dispatched two ships to help take 629 migrants stuck off its shores to Spain after the new populist government refused them safe port in a bid to force Europe to share the burden of unrelenting arrivals.
The rescue ship Aquarius has been stuck since Saturday in international waters off the coast of Italy and Malta, both of which have refused it entry.
The ship is carrying 629 migrants including 123 unaccompanied minors, 11 children and six pregnant women.
Aid group Doctors Without Borders, which operates the Aquarius with SOS Mediterranee, urged Italy and Malta to reconsider their refusal to allow the stranded migrants landfall and then safe passage by other means to Spain, which has responded to the plight with an offer of safe harbour.
The aid group warned of severe health risks to a significant number of the passengers.
Italy's new anti-migrant interior minister Matteo Salvini is making good on a campaign pledge to close Italian ports to non-governmental organisations that pick up migrants at sea, which he has likened to taxi services for migrant smugglers.
Mr Salvini, whose League party is part of the populist coalition that took office this month, promised voters that other European countries would be made to share the burden of caring for asylum-seekers arriving in Italy on unseaworthy boats mostly from lawless Libya, while taking particular aim at the aid vessels.
"These are all foreign ships flying foreign flags that bring this human cargo to Italy," Mr Salvini told private television La7.
"We have hosted 650,000 migrants in recent years alone, all of whom pass by Malta, an EU country, and the government says, 'Ciao, Ciao, go to Italy'. I am happy to have given a small first response."
While Mr Salvini turned away the Aquarius, an Italian coastguard vessel with more than 900 migrants rescued in seven operations is expected to reach Italy's shores on Wednesday.
Meanwhile, hundreds of migrants aboard the Aquarius were being transferred to ships operated by the Italian navy and coastguard, which are then to accompany the aid ship to the Spanish port of Valencia.
Many remained on the deck of the overcrowded rescue ship and were told their safety was at risk for the longer voyage given the forecast of bad weather, said SOS Mediterranee spokeswoman Mathilde Auvillain.
The Italian coastguard said fresh provisions had been delivered to the Aquarius on Tuesday.
Officials in Valencia said they expected the ship to arrive in three to four days, depending on when they depart and weather conditions.
The new Spanish foreign minister said Spain's decision in accepting the migrant ship is also meant to push European Union leaders to address the bloc's migration policies later this month at an EU summit.
"Spain has made a gesture that aims to trigger a European dynamic to stop looking away, allowing one (EU member) to cope with the problem while the rest of us pass the buck," Josep Borrell said.
The decision to offer a docking port in the eastern city of Valencia had been a personal and direct move by the country's new prime minister, the Socialist Pedro Sanchez.
Many Spanish regions and cities have offered to provide long-term support to the migrants, said Valencia's regional vice president Monica Oltra.
The Red Cross is preparing shelter and medical assistance to meet immediate needs on their arrival.
