The Minister for Defence Simon Coveney is extending the Irish Naval Service mission in the Mediterranean.
The L.E Samuel Beckett will be deployed to replace the L.E Niamh from the end of September until the end of November.
The Irish Navy has been helping Italian authorities in search and rescue operations involving migrants.
So far, the L.E Eithne and the L.E Niamh have rescued around 6,000 migrants from the Mediterranean.
“While our role in the Mediterranean is making an impact in the short term in terms of saving lives, longer-term solutions to address the migrant crisis are needed.”
Last month the LE Niamh rescued 125 people from a large inflatable rib some 70 miles (115km) north-west of Tripoli.
Earlier, the ship’s crew saved 367 people from drowning after a fishing vessel with some 600 people on board capsized north-west of Tripoli. The ship brought the rescued and 25 bodies to Sicily.
Mr Coveney said he will be meeting EU colleagues tomorrow in Luxembourg to discuss a range of issues including progress on the EU military mission in the Mediterranean (EUNAVFOR MED).
“A comprehensive approach is required to address this complex crisis with a view to developing longer-term solutions,” he said.
The European Union has announced emergency talks on September 14 to deal with the worsening migration crisis.
Austria is increasing checks on lorries near its eastern borders following the discovery of 71 dead migrants in a lorry near the border with Hungary.