Seoul and Washington have struck different tones in recent months over the possible deployment of an advanced missile defense system here.

A senior Pentagon official prompted the latest controversy by confirming last week that the U.S. is considering deploying the Terminal High-Altitude Area Defense system in South Korea to better cope with threats from North Korea. Deputy Secretary of Defense Robert Work said, “We are working with the government of South Korea now to determine if that is the right thing to do.”

His remark, which was made during a forum in Washington, contrasted with what South Korean officials have claimed so far ― that the U.S. has not officially asked to deploy the THAAD system here and the two sides have not held any discussions on the issue. Seoul’s Defense Ministry reiterated this stance a day after Work made public Washington’s intention to put a THAAD battery in South Korea.

The U.S. Defense Department later said Washington has made no decision and held “no formal consultations” on the issue with Seoul. But another U.S. defense official still hinted at the possibility of deploying the advanced system here, hoping to be able to work with Seoul to “meet any potential missile threat to South Korea or to the region.”

Some experts here see it as only a matter of time before the U.S. sends a THAAD battery to South Korea, expecting the allies to reach a final decision on the matter when their defense chiefs hold annual security talks in Washington later this month. In a move that could be seen as being connected, the two sides may also agree on details on postponing the planned transfer of wartime operational control of South Korean forces from Washington to Seoul.

It is understandable that Seoul officials remain cautious on the deployment of the THAAD system ― a sensitive issue that could strain South Korea’s ties with China and Russia, which regard it as targeting their intercontinental ballistic missiles as well as threats from North Korea. Washington also appears to be putting pressure on Seoul to buy the costly system, which constitutes a key component of the U.S.-led global missile shield program.

But South Korea needs to establish its position on the THAAD deployment from a strictly military viewpoint. The system’s capability to intercept incoming missiles at higher altitudes than its own planned missile defense scheme would make the allies better prepared to handle threats from North Korea, which has conducted a series of rocket tests this year. Seoul officials should point this out to Beijing and Moscow in a more public manner, asking for closer cooperation from them in curbing Pyongyang’s nuclear and missile development programs.

A commitment to building a stronger defense posture would help facilitate, not hamper, a thaw between the two Koreas in the near future.