Tuesday's extraordinary meeting comes after criticism governments took an overcautious approach to the crisis.

Flights resumed when manufacturers gave assurances six days after the eruption, which disrupted the plans of hundreds of thousands of people last month.

The meeting comes as the Irish Aviation Authority (IAA) suspended flights in and out of Ireland for six hours on Tuesday as the Icelandic volcanic ash cloud returned.

The IAA said restrictions would be imposed from 0700 to 1300 BST as a plume of ash drifted across the country.

Ryanair flights to and from Belfast City Airport have been cancelled until 1400 BST on Tuesday due to volcanic ash drifting from Iceland. And the UK's Civil Aviation Authority also announced a closure of air services over Scotland's outermost Hebrides islands on Monday night.

EU transport ministers are now under pressure to speed up implementation of a plan that would introduce trans-national airspace blocks.

The European Commission has said that during the crisis the EU member states were applying risk assessment models in line with guidelines laid down by the International Civil Aviation Organization (ICAO), a United Nations agency.