The ballistic missile that North Korea fired over Japan Tuesday was a medium-range rocket that did not threaten US territory, the Pentagon said.

"Initial assessment indicates the launch of an intermediate range ballistic missile (IRBM)," the Pentagon said in a statement.

"The North American Aerospace Defense Command determined this ballistic missile launch did not pose a threat to North America. US Pacific Command determined this ballistic missile launch did not pose a threat to Guam," it said.