Secretary of Defense Mark Esper said Monday that "we will follow the laws of armed conflict" as they relate to the targeting of cultural sites, which is considered a war crime, CNN reports.

Why it matters: The remark appears to contradict President Trump's threat Sunday to target 52 Iranian sites — including ones "important" to Iranian culture — as a response to a potential retaliatory attack by Iran.

Appearing on the cable talk shows Sunday, Secretary of State Mike Pompeo offered a similarly vague response. Pompeo refused to directly disavow Trump's statement, but said that "we'll behave lawfully" and "inside the system."

But, but, but: Trump has continued to double down on the threat.

On Sunday, the president told reporters: "They’re allowed to kill our people. They’re allowed to torture and maim our people. They’re allowed to use roadside bombs and blow up our people. And we’re not allowed to touch their cultural site? It doesn’t work that way."

Go deeper: The Met calls Trump's threat to target Iranian cultural sites "abhorrent"