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

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

“Express with us the concern, outrage ... with regard to Iran’s activities in the region. That would be a good first step,” Esper said, when asked during his flight to Brussels what he wanted to see from allies in the North Atlantic Treaty Organization.

“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, to close the door to conflict and open the door to diplomacy.”