Defense Secretary Jim Mattis’ inaugural overseas trip is aimed at reassuring Asian allies. (Franck Robichon/EPA)

Defense Secretary Jim Mattis said Saturday that the threat from Iran’s missile program does not currently require the realignment of U.S. forces in the Middle East, striking a note of restraint shortly after the White House issued a strong warning to Tehran.

Mattis, on a three-day visit to South Korea and Japan, echoed statements from the White House identifying Iran as a chief danger to U.S. security after a recent ballistic missile test.

On Thursday, Michael Flynn, President Trump’s national security adviser, told reporters that the new administration was “officially putting Iran on notice.” He provided no details on what that may mean.

But Mattis, a former commander of U.S. operations in the Middle East and a hawk on Iran, said the United States did not need to add military assets, potentially including additional troops or an aircraft carrier, to the region.

Mattis’ inaugural overseas trip is aimed at reassuring Asian allies concerned by Trump’s questioning of longstanding U.S. security alliances.

Speaking at a news conference in Tokyo, Mattis called Iran the world’s “single biggest state sponsor” of terrorism.

“I think it’s wise to make certain that Iran recognizes that what it is doing is getting the attention of a lot of people,” he said. “It does no good to ignore; it does no good to dismiss it, and at the same time, I don’t see any need to increase the number of forces we have in the Middle East at this time.”

Mattis’ comments raise additional questions about whether Trump’s new national security team can come together on major issues facing the United States.

The retired Marine general gave a similar answer to a question about the South China Sea, where Beijing is seeking to assert control over areas claimed by other Asian nations. China has launched a major campaign of building up artificial islands and has installed equipment that analysts believe is military in nature.

Trump’s new secretary of state, Rex Tillerson, said during his confirmation hearing that the United States should block China’s access to those areas. White House press secretary Sean Spicer has also made similar remarks.

Speaking to reporters at the Japanese Defense Ministry, Mattis said that military action was not now needed to counter China’s actions.

“What we have to do is exhaust all efforts, diplomatic efforts, to try to resolve this properly, maintain open lines of communication,” he said. “Certainly our military stance should be one hat reinforces our diplomats in this regard. But there is no need right now, at this time, for military maneuvers or something like that that would solve something that’s best solved by the diplomats.”

Mattis did say that freedom of navigation remained a core principle for the U.S. military and said U.S. ships would continue to transit international waters.