U.S. Secretary of State Mike Pompeo announced on Monday that the U.S. will apply economic and military pressure against Iran and will impose “the strongest sanctions in history” on the Islamic Republic.

“Sanctions are going back in full effect, and new ones are coming,” CNN quoted him as saying in his speech at the Heritage Foundation.

It was the first major speech to lay out a new strategy after the U.S. President Donald Trump withdrew from the 2015 nuclear deal on May 8.

“The sting of sanctions will be painful if the regime does not change its course from the unacceptable and unproductive path it has chosen to one that rejoins the league of nations,” Pompeo said.

He said relief from sanctions would only come when the U.S. had seen tangible shifts in Iran’s policies.

He said Washington would be open to a new treaty and wanted the support of America’s allies.

“Iran will never again have carte blanche to dominate the Middle East,” he said.

Pompeo noted that the Trump administration was ready to part ways with allies and even use sanctions against them if necessary.

“We understand our re-imposition of sanctions and the coming pressure campaign on the Iranian regime will pose financial and economic difficulties for a number of our friends,” Pompeo said. “But you should know that we will hold those doing prohibited business in Iran to account.”

In exchange for a change in behavior, Pompeo claimed that the U.S. would be willing to end sanctions, re-establish commercial relationships and allow it to have advanced technology.

Elsewhere, Pompeo criticized the nuclear deal for what he called its “fatal flaws”.

On May 8, Trump declared U.S. pullout from the international nuclear agreement, officially known as the Joint Comprehensive Plan of Action.

The nuclear deal was signed in July 2015 between Iran, Germany, the European Union and the five permanent members of the UN Security Council. It went into effect in January 2016.

International Atomic Energy Agency has reported ten times that Iran has been committed to the nuclear deal.

Federica Mogherini, the EU’s foreign policy chief, issued a statement on Friday saying that the 28-nation bloc is united in preserving the international nuclear deal.

Germany and four other nations - France, Britain, Russia and China - will soon meet to discuss how to proceed with the nuclear deal, German newspaper Welt am Sonntag reported on Sunday.  The meeting will be led by senior European Union diplomat Helga Schmid.

Iranian Foreign Minister Mohammad Javad Zarif said on Sunday the European Union’s “political support” for the multilateral nuclear agreement is not enough, urging the bloc to take more practical steps to boost economic cooperation with Iran.

With the U.S. pullout, Iran’s public expectations from the EU have increased in order to maintain the benefits of the deal, Zarif told EU’s energy chief, Miguel Arias Canete, in Tehran.

The EU should take more practical steps and increase its investments in Iran for continuation of economic cooperation with Iran, the foreign minister said.

Canete, for his part, voiced European countries’ determination to preserve the JCPOA and to support the cooperation between European companies and Iran.

He added that the U.S. withdrawal from the JCPOA had created problems for Europe, but the EU will continue cooperation with Iran in maintaining and protecting the JCPOA.