BRUSSELS, May 8 (Xinhua) -- European Council President Donald Tusk on Tuesday expressed his disapproval over U.S. President Donald Trump's decision to pull out of the landmark Iran nuclear deal, saying the move "will meet a united European approach."

"Policies of @realDonaldTrump on #IranDeal and trade will meet a united European approach," Tusk tweeted, minutes after Trump announced his decision to withdraw from the Iran deal.

"EU leaders will tackle both issues at the summit in Sofia next week," Tusk added

Riding roughshod over opposition across the pond, Trump said in a televised speech that the United States will withdraw from the Iran nuclear deal, a landmark agreement signed in 2015 by Iran and six world powers, including EU heavyweights Britain, France and Germany.

Trump added he will not sign the waiver of nuke-related sanctions against Iran.

In the past weeks, the EU and the three heavyweight member states had made last-ditch diplomatic efforts to persuade Trump not to back out of the deal.

The soon-to-be-27 bloc is set to stage the EU-Western Balkans summit in Sofia, Bulgaria, on May 17.

It seems that Trump's announcement threw a wrench into the EU's plans on the summit, which is supposed to be centered on the topic of improving the links between the bloc and the Western Balkans.

In tandem with Tusk's disapproval over Trump's announcement, EU foreign policy chief Federica Mogherini vowed that Europe will stand by the international nuclear accord with Iran.

"The EU is determined to preserve it," she said in a live press statement in Rome. "We expect the rest of the international community to continue to preserve it, for the sake of collective security."