In 1999, North Korea agreed to a moratorium on long-range missile testing, and has not fired one since.

The Air Force tests conducted during the spring were inadequate, so missile testing needed to continue and modifications needed to be made during the summer.

For more than a year the North has abided by an agreement to suspend long-range missile testing.

President Clinton's approach to North Korea wasn't pretty but it did eventually stop both plutonium production and missile testing.

In September 1999, North Korea agreed to a moratorium on long-range missile testing.

We were under a contract to do some missile testing, and it was scheduled for later that morning.

The agreement on missile testing, disclosed on Sunday, is very limited, far from explicit and of unknown duration.

Kim Jong-un has clearly communicated intent to continue with ballistic missile testing, however the time line on future tests remain unclear.

The Union is also concerned about possible new missile testing.