The United States should consider offering to call off the planned deployment of the THAAD missile defense system to South Korea if Beijing imposes serious sanctions on North Korea, US experts said Monday.

Eric Heginbotham and Richard J. Samuels of the Massachusetts Institute of Technology's Center for International Studies made the suggestion, arguing that flexibility on THAAD deployment is worth an end to the North's nuclear and missile programs.

"US leaders should not only point out the downside of Chinese inaction. They should put an offer, or set of offers, on the table.

If China agrees to impose a serious and graduated set of sanctions on North Korea -- ones that the North cannot ignore -- the United States might agree to freeze the deployment of GBI at their current number (and reduce the number as North Korea reaches milestones in dismantling its weapons programs)," the researchers said, referring to ground-based interceptors.

"The United States might also agree, after consulting South Korea, to withdraw THAAD from the peninsula when North Korean nuclear weapons no longer pose a threat," they said in a joint article published on the website of the National Interest magazine.

But both GBIs and the THAAD deployment to South Korea have been justified exclusively on the basis of the North's nuclear and missile threats, and "flexibility on the deployment of those systems would be well worth a verifiable end to the North's WMD programs," they said.

Their suggestion came amid concern that China could be lukewarm about efforts to impose fresh sanctions on Pyongyang for its fifth nuclear test in retaliation of the decision by Seoul and Washington to deploy the Terminal High Altitude Area Defense battery to the South.

Beijing has strongly protested the decision, claiming that the advanced missile system, especially its powerful "X-band" radar, can be used against it, despite repeated assurances from the US and the South that the system is purely defensive and designed only to cope with North Korean threats.

"Beijing, which suspects that X-band radar associated with US THAAD in South Korea might also track Chinese missiles, is unlikely to change course based solely on US assurances about future moderation of US strategic deployments. The bargain outlined above is not meant to change China's perspective or its view of its own national interests," the researchers said.

"Rather, it presupposes that North Korea's most recent provocations may bring Beijing to recalculate the costs of its inaction. We believe that a forthright US acknowledgment of China's own security equities and a willingness by Washington to compromise might help tip the balance in Beijing and pacify the Korean Peninsula," they said. (Yonhap)