U.S. Secretary of State Mike Pompeo is due to announce on May 21 a new U.S. strategy for dealing with Iran in his first major address taking over the job last month.

Pompeo will outline a "diplomatic road map" for reaching a new nuclear deal with Iran in a speech (EDS: 1500 Prahue time) at the conservative Heritage Foundation in Washington.

The new approach will seek to create "a framework that will address the totality of Iran's threats," a State Department official said last week.

The official did not provide details on the speech, but said it would focus on revisions to the deal that address concerns about so-called sunset clauses allowing some of the restrictions of the deal to expire over time, Iran's ballistic missiles, its "stoking" of civil wars in the region, and a better inspections regime.

Pompeo's speech will come two weeks after President Donald Trump unilaterally withdrew the United States from the landmark 2015 Iran nuclear accord and reinstated economic sanctions against Tehran.

The State Department said Pompeo held consultations with the foreign ministers of Germany, France and Britain - the European signatories of the deal -- ahead of his speech.

All remaining signatories have pledged to stay in the agreement even without U.S. participation. China and Russia are the other countries in the agreement.