The United States hopes to conduct ongoing antimissile drills with Japan and South Korea as part of a program of defense against North Korea's ballistic missile capabilities, the Yonhap News Agency reported on Monday.
"The U.S. considers boosting trilateral cooperation with the regional allies as an option," according to an unidentified insider in Washington.
The allies during the 2012 Pacific Dragon maneuvers monitored two mock ballistic missiles fired at nearly the same time. Washington hopes for a follow-up exercise in 2013 and then to continue the collaborative practices.
North Korea in recent months has demonstrated advances in its nuclear arms and missile operations, sending a rocket into space in December and conducting its third underground atomic test in February.
Washington has already shifted its antimissile priorities toward the North's threat, announcing plans to deploy another 14 long-range interceptors in Alaska while canceling plans for a next-generation weapon that would have been fielded in Europe to counter the Iranian missile threat.
Seoul has appeared skeptical of overinvolvement in U.S. ballistic missile defense cooperation, focusing instead on its "Korea Missile Defense" effort.