The Netherlands have refused Italy's request to take in 47 migrants currently on board a Dutch-flagged rescue ship that Italian ports have refused to allow to dock.

The Sea Watch 3 ship, run by a German NGO, rescued the mainly sub-Saharan African migrants off Libya more than a week ago and is currently sheltering from bad weather off Sicily.

Italy and Malta have both refused to let it dock.

"Without a firm idea of an overall solution, the Netherlands will not take part in ad hoc measures for disembarkation" of the ship, Lennart Wegewijs, a spokesman for the Dutch Justice and Security Ministry, told AFP.

Italy's far-right Interior Minister Matteo Salvini has insisted Germany or the Netherlands take responsibility for the migrants, warning that he was considering legal action against the crew.

Last week, he said Italy's ports were closed and the migrants should be disembarked in Malta and sent to The Netherlands.

But German and Dutch authorities insist the problem should be solved within the wider context of an elusive EU migration deal that distinguishes between people in need of asylum, and economic migrants. 

The Dutch government said it was not its responsibility because the boat had acted "on its own initiative... It was up to the captain of Sea Watch 3 to find a nearby port to disembark the 47 migrants he had on board". 

EU rules say that the country where migrants land should be responsible for dealing with any asylum claims.

READ: The Netherlands ready to take in some Sea Watch migrants

In early January, the EU reached a deal with eight countries to share out migrants on board two ships sheltering off Malta, one of which had been the Sea Watch 3. The Netherlands had been one of those countries.

Migrants rescued by ships have frequently been left in limbo since Italy's anti-immigration government began turning them away last summer.

Some 113,482 migrants crossed the Mediterranean to reach Europe last year, according to the UN refugee agency, which said 2,262 people lost their lives or went missing making the perilous journey.

Europe has been wrestling with the issue since the migration crisis of 2015 when more than one million people arrived on its shores, many of them fleeing conflict in the Middle East.