After summit talks in Moscow earlier this week, Chinese President Xi Jinping and Russian President Vladimir Putin made the so-called "freeze-for-freeze" proposal in an effort to defuse escalating tensions on the Korean Peninsula.

The North has previously made a similar proposal but the US has flatly rejected it, saying it makes no sense for the US to halt the lawful exercises in return for the North suspending its illicit weapons activities.

"There's no equivalency between the United States and its activities and actions that it undertakes with its allies, including South Korea and also Japan. These are something that are lawful," State Department spokesperson Heather Nauert said at a regular briefing.

North Korea has long called for an end to annual joint exercises between the US and the South, denouncing the drills as a rehearsal for invasion. Washington and Seoul have rejected the demand, saying the exercises are purely defensive. (Yonhap)