"The European summit on Thursday cannot be an ordinary summit where we take ordinary decisions. We must go much further… and tackle these questions which have become intolerable," he said.
On Monday, the EU unveiled a ten-point action plan to stem the tide of migrants crossing the Mediterranean, promising to step up both control and rescue operations.
The European Commission said the plan, approved by EU foreign and interior ministers at an emergency meeting in Luxembourg, will be submitted at Thursday's summit as the 28-member bloc tries to halt a growing death toll off its southern shores.
The ten-point plan calls first for the current Triton maritime frontier mission to be stepped up, both in funding and resources so it can cover a wider issue.
Triton replaced Italy's Mare Nostrum mission which Rome scrapped late last year in protest that its EU partners did not share the burden of the cost.
The EU will also try to capture or destroy people smuggler boats and increase cooperation across the board, the Commission said.
The bloc will offer too a "voluntary pilot project on resettlement, offering a number of places to persons in need of protection," a key but small step forward in spreading out the problem.
Diplomats said this could cover 5,000 places but the Commission statement gave no figure.
Additionally, the EU will "establish a new return programme for rapid return of irregular migrants."
It will also step up cooperation efforts with neighbours of war-torn Libya, the epicentre of the problem, the statement said.