The top national security adviser says President Donald Trump would be �pretty disappointed� if North Korea were to launch a new rocket or missile test, as some experts believe he could be preparing to do.

Speaking on ABC�s �This Week,� John Bolton would not confirm reports based on commercial satellite imagery that North Korea is making moves, saying he�d rather not go into specifics.

But he says the U.S. government is watching North Korea �constantly,� and that, �Nothing in the proliferation game surprises me anymore.�

He also says Trump would �be pretty disappointed if Kim Jong Un went ahead and did something like that� after he vowed not to at a summit in Vietnam.

The new activity was detected at a North Korean missile research center and long-range rocket site.

(AP)