"We are not seeking conflict with Iran. We want to engage with them diplomatically," Esper said in his first formal press conference after being confirmed last month.

"The president said once again he is willing to meet with Iran's leaders," he said.

"We hope that the Iranians would agree to meet and talk and help us resolve these issues."

At the G7 meeting in Biarritz, France on Monday, Trump, whose government has aggressively sought to pressure Tehran, showed openness to French President Emmanuel Macron's proposal of a summit with his Iranian counterpart Hassan Rouhani.

"If the circumstances were correct, I would certainly agree to that," Trump said at a joint press conference with Macron.

That could be the ice-breaker needed to end more than two years of heightened hostilities between the two countries.

Breaking with his predecessor Barack Obama, Trump enacted a policy of "maximum pressure" on Tehran over its disputed nuclear program and last year unilaterally withdrew from the landmark 2015 international deal that placed limits on Tehran's nuclear activities.

Tensions over that move have gradually risen, with Iran seizing tankers in the Gulf in recent months and Britain detaining an Iranian tanker off of Gibraltar.

In the wake of that, the US launched its "Operation Sentinel," a naval operation to protect commercial shipping in the Gulf.

"I am pleased to report that Operation Sentinel is up and running, with the UK, Australia and Bahrain joining us in this effort," Esper said.

He said other countries would likely soon join, and that the operation had helped calm the region.

"Between our presence and the presence of our allies and partners in the region, I think so far, further bad, provocative behavior has been deterred," Esper said.

"We want to talk to Iran, and talk about a diplomatic path forward," he said, adding: "I'm not sure I'm ready to call the crisis over yet. So far, so good."