WASHINGTON (Reuters) - Acting U.S. Defense Secretary Mark Esper said on Tuesday he aimed to recruit support from NATO allies for U.S. efforts to deter conflict with Iran and “open the door to diplomacy,” as he made his international debut as Pentagon chief.

U.S. acting Secretary of Defense Mark Esper arrives for the first day in his new post at the Pentagon in Arlington, Virginia, U.S. June 24, 2019. REUTERS/Jonathan Ernst

Esper emphasized diplomacy over military action as he briefed reporters for the first time since taking the helm of the U.S. military on Monday. The former Army secretary was thrust into the position after the surprise resignation of Patrick Shanahan as acting defense secretary the previous week.

Ahead of talks with European defense ministers, Esper said he would tell allies that the United States was not seeking war with Iran.

His remarks came just days after U.S. President Donald Trump narrowly called off strikes against military targets in Iran over Tehran’s downing of a U.S. drone. But Trump threatened on Tuesday to obliterate parts of Iran if it attacked “anything American.”

“We need to internationalize this issue and have our allies and partners work with us to get Iran to come back to the negotiating table,” Esper said shortly before landing in Brussels, home to NATO headquarters.

Washington’s European allies, critical of Trump’s decision to withdraw from a 2015 nuclear deal with Iran, have reacted with alarm in recent weeks, repeatedly warning both sides of the danger that a small mistake could lead to war.

U.S. officials said on Monday that the United States was building a coalition with its allies to protect Gulf shipping lanes following recent attacks on oil tankers that Washington blamed on Iran.

But Esper suggested the plan was still in its early stages and played down the idea that U.S. allies would offer up the majority of ships, saying: “Nobody’s counting ships or compositions at this point in time.”

Asked what he wanted U.S. allies to do on Iran, Esper said: “Express with us the concern, outrage ... with regard to Iran’s activities in the region. That would be a good first step.”

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“And then secondly, to support any range of activities we may think merit participation to help, again, deter conflict and show that we’re resolute. What we’re trying to do, what we want to do, is to close the door to conflict and open the door to diplomacy.”

NATO “SPEED DATING”

Esper is now the third person in six months to work at the defense secretary’s desk, stoking fresh questions about leadership at the Pentagon.

For many NATO allies, this week’s NATO defense ministerial will be a unique chance to get an early sense of Esper, who has deep roots in the U.S. military, Congress and even the U.S. defense industry.

It will be a similar opportunity for Esper, who said he aimed to emphasize to NATO allies that the change in leadership at the Pentagon did not represent a change in policy.

“A NATO ministerial is a good way to get to know key partners, kind of like diplomatic speed-dating,” said Derek Chollet, a former senior Pentagon official during the Obama administration.

Chollet said allies would be closely watching for hints about the kind of role Esper will play, including whether he might be like Jim Mattis, Trump’s first defense secretary who was a strong advocate for NATO and was seen as a moderating influence on the U.S. president.

Mattis, who resigned in December over policy differences with Trump, brought Esper into the job.

One European diplomat joked: “Jim Mattis is not someone we can clone, as much as we’d like to, but Esper is talked about positively.”

“Everyone will want to make a good impression and to get some time because he is the new face of the Pentagon,” the diplomat said.