EU foreign and interior ministers are due to meet in Luxembourg to discuss the deaths of migrants trying to cross the Mediterranean from Africa.
Some southern European nations say the EU’s credibility is now at stake after last year’s decision to scale back search and rescue efforts.
In the latest tragedy, hundreds are believed to have drowned after their boat sank off Libya at the weekend.
The UN says the North Africa-Italy route has become the world’s deadliest.
The 20m (70ft) boat was believed to be carrying up to 700 migrants, and only 28 survivors have been rescued.
A boat carrying coffins of the 24 victims found so far has just arrived in Malta, the Italian coastguard says.
Another vessel carrying dozens of migrants has run aground off the coast of the Greek island of Rhodes, killing at least three people, the Greek coastguard has said.