Brussels, Apr 17 (IANS/DPA): European Union (EU) leaders are in Brussels for a two-day summit starting from Wednesday to discuss the EU's economic future, the Ukraine war and major tensions between Israel and Iran.

The EU must "unite in urging all parties to exercise the utmost restraint, respect international law, and avoid action that may increase tensions," European Council President Charles Michel said in a statement ahead of the summit.

What was supposed to be an in-depth strategic review of the EU's economic competitiveness has been overshadowed by events in the Middle East.

Iran directly attacked Israel on Saturday for the first time in the history of the Islamic Republic.

Iran said the drone and missile attacks were in retaliation for the killing of high-ranking Iranian officers in Syria at the start of the month.

EU leaders plan to discuss whether and, if so, how the EU could contribute to a de-escalation in the region.

Other foreign affairs issues to be discussed include the impact of regional instability in the Middle East on Lebanon and the bloc's relations with Turkey.

Ukrainian President Volodymyr Zelensky is invited to address the assembled EU leaders via video conferencing and has urged Ukraine's allies to supply his country with more air defence systems.

On the last day of the meeting, former Italian Prime Minister Enrico Letta will present a report on the future of the EU's single market, the bloc's economic regulatory system that allows goods, money, services and people to move freely across the 27 EU member states.