TOKYO, Japan # In a move likely to add to rising tensions on the Korean Peninsula, North Korea may be readying to test fire a medium-range ballistic missile, Japan’s Kyodo news agency reports.

Quoting an unnamed senior U.S. official, Kyodo reported that the U.S. was monitoring North Korean missile activity closely.

“At this point, what we’re concerned about is the Rodong,” the official, in Washington was quoted as saying.

The Rodong missile, with a range of about 1,300 km (800 miles) is capable of striking Japan. Defense analysts believe around 100 of the missiles have been deployed in North Korea.

“There is various activity,” the official said. “There is nothing concrete to show that they are doing that, but we do have worries both logically and in terms of some movements we are seeing that might make sense.”

There have been a number of military related maneuvers in the past fortnight that have added to tensions on the Korean Peninsula.