"North Korea's military stationed at the truce village of Panmunjom said that regardless of the location, they can not avoid North Korea's ruthless firing".
The latest test took place on July 4, when Pyongyang said it had successfully launched its first intercontinental ballistic missile (ICBM), the Hwasong-14.
Moon has said he would use both dialogues and pressures to resolve the standoff over North Korea's nuclear program.
He also addressed reports of North Korea launching missiles in May, asserting that North Korea had shown the Chinese "great disrespect" and that China was "trying hard" to get them to stop.
"Meeting with their families while they are alive must be prioritized more than any other political concerns", said Kim Sun-hyang, acting president of South Korea's Red Cross.
The joint statement commits the three leaders to work together to counter the threat from North Korea and "to apply maximum pressure" on Pyongyang "to change its path, refrain from provocative and threatening actions, and take steps necessary to return to serious denuclearization dialogue".
70 percent say Trump acts unpresidential
The 40 percent rating by those who agree with Trump on issues is among the lowest given to presidents since the survey began. Other key findings reveal that 61 percent of respondents say America is on the wrong path - up 12 points since December.
The Trump administration has yet to see what it considers a sufficient response from China. Inter-Korean cooperation and aid have come to a full stop over the last nine years under the conservative governments and global sanctions following North Korea's deadly attacks to South Korea and missile and nuclear tests. "The president is fully aware of those", said Gorka.
During the meeting, U.S. Ambassador to the UN - Nikki Haley - announced the U.S.'s intention to introduce a new resolution in the "coming days" in order to "raise the worldwide response in a way that is proportionate to North Korea's new escalation".
The UNSC is working on a new set of punitive actions against the North following its sanctions resolutions adopted after last year's two nuclear tests.
But they would stop short, at least for now, of the kind of broad "sectoral" sanctions Mr Trump's predecessor, Barack Obama, secured through unilateral and worldwide action against Iran to pressure it into negotiations to curb its nuclear program.
But in recent weeks, Mr Trump has fired off tweets denouncing China's trade with North Korea and cast doubt on whether Beijing was doing enough to counter Pyongyang. Oil products are sold by weight in North Korea.