He also called on Pyongyang to reverse its course of provocations for the resumption of dialogue while warning that his administration would deal resolutely with its provocations in order to ensure it would not "miscalculate" the situation.
"Even if dialogue is possible, (we) should show (to North Korea) that it's possible only in case of North Korea changing its attitude," Moon said, presiding over a session of the National Security Council.
Earlier in the day, North Korea launched a ballistic missile from a site about 100 kilometers north of Pyongyang, South Korea's military said.
"North Korea fired an unidentified missile at around 5:27 a.m. today from an area in the vicinity of Kusong, North Pyongan Province," the Joint Chiefs of Staff (JCS) said in a statement.
The projectile flew some 700 kilometers, it said, adding it's analyzing more details. The flight distance suggests the success of the missile test.
The North test-fired a Pukguksong-2 intermediate-range ballistic missile (IRBM), also known as the KN-15, from the same site on Feb. 12.
Moon ordered his troops to bolster deterrence against the North's military threats on the basis of the robust alliance with the United States.
In particular, he instructed the military to speed up the establishment of South Korea's own missile defense system, called the Korea Air and Missile Defense (KAMD).
The U.S. Pacific Command, based in Hawaii, also announced that it detected and tracked the launch of the missile, which landed in the East Sea.
"The type of missile is being assessed, and the flight was not consistent with an intercontinental ballistic missile," it said. "The U.S. Pacific Command is fully committed to working closely with our Republic of Korea and Japanese allies to maintain security."
The Japanese government said the North's missile flew for half an hour. Prime Minister Shinzo Abe criticized the North for again violating the U.N. Security Council resolutions.
The JCS said, "Our military is maintaining a full defense posture, closely monitoring the North Korean military's move." (Yonhap)