Europe must do more to help migrants crossing the Mediterranean, UN chief Ban Ki-moon said on Tuesday ahead of a visit to Brussels, as a planned EU naval operation awaits UN Security Council approval.

Europe "can provide more help," Ban said at a joint press conference in Dublin with Irish Prime Minister Enda Kenny, calling for search and rescue operations in the Mediterranean to be "further strengthened".

"I’m urging European leaders to address this issue in a more comprehensive way and a collective way," he said, adding that any approach should also look at the "roots" of the problem in countries of origin.

"Without compassion you cannot do this. We have to first of all do our best to save lives." 

EU foreign policy chief Federica Mogherini said she hopes to discuss with Ban a "very important issue, which is the link between development, cooperation and migration." 

"We always say that we have to tackle the root causes of the phenomenon," the former Italian foreign minister added.

"Today with the ministers for development and Ban Ki-moon we have a perfect chance to look at how the European Union and the partner countries, especially in Africa, can develop more possibilities for African citizens to face a better present and a better future," she said.

EU ministers last week approved plans for a military operation to fight Mediterranean people smugglers, although proposals to destroy traffickers’ boats in Libyan waters still need UN approval.

The European Commission has also unveiled plans to make the rest of the 28-nation EU share the burden of frontline states such as Italy, Greece and Malta, although some countries like Britain are opposed.

So far this year, some 1,770 migrants have perished on the hazardous journey to Europe, according to the International Organisation for Migration, a 30-fold increase on the same period in 2014.

Ban last week visited Vietnam and called for the migrant crisis in Southeast Asia to be made a "top priority" there, as the region battles with an exodus of boat people fleeing persecution and poverty.

Many of them are Muslim Rohingya from Myanmar’s western Rakhine state, where they are not recognised as citizens.