WASHINGTON _ Defense Secretary James Mattis said Monday that the U.S. military has not attempted to shoot down ballistic missiles test-launched by North Korea because they have not been on a trajectory to hit U.S. or allies' territory.
The comments come after the underground test of a nuclear bomb this month and days after North Korea launched its second missile in less than a month to fly over northern Japan.
The intermediate-range missile was launched Friday near the isolated nation's capital, Pyongyang, soaring for about 2,300 miles before falling into the Pacific Ocean. The test demonstrated that the U.S. territory of Guam is now in range of a North Korean attack.
Mattis said the launches are testing the U.S. military to see how much North Korea can get away with before triggering a response.
"They are intentionally doing provocations that seem to press against the envelope to see how far they can push without going over some kind of line in their minds that would make them vulnerable," he said.
"The bottom line is: The missiles, were they to be a threat �� whether it be to U.S. territory, Guam, (or) obviously Japan's territory _ that would elicit a different response from us," he said.
The U.S., Japan and South Korea have missile defense systems surrounding North Korea, including at sea. Analysts have stressed that knocking a missile out of the sky with interceptors is difficult and has been often been described as "hitting a bullet with a bullet."
North Korea has conducted 15 missile tests in 2017 and more than 60 since Kim Jong Un took power in 2011.
Thus far, U.S. response to the launches has been sanctions, which have largely cut off Pyongyang from the rest of the world economy, and "show of force" exercises.
On Sunday, U.S. Air Force flew B-1 bombers and F-35 stealth fighter jets over the Korean Peninsula with allied fighter jets from South Korea and Japan.
