U.S. Defense Secretary Mark Esper said on Tuesday he has not issued orders to reduce the number of troops based in South Korea, but has left the door open for such a move in the future.

Esper made the remarks during a virtual event hosted by the International Institute for Strategic Studies when asked about a Wall Street Journal report that said the Pentagon presented the White House with options to reduce troops in South Korea in March.

The Pentagon chief said he has issued no orders to withdraw forces from the Korean Peninsula, but the U.S. will continue to look at "adjustments" at every command it has in every theater to make sure it is optimizing its forces.

Esper added that he wants to continue to pursue more "rotational force deployments" because they give the U.S. "greater strategic flexibility" in responding to global challenges.  

The remarks are the Pentagon chief's first response to the Wall Street Journal article.