Stressing that he did not exclude North Korea's "unpredictable" leader Kim Jong-un would use nuclear weapons, Foreign Minister Laurent Fabius said on BFM-TV that he would travel to China next week to discuss the situation.
The Korean peninsula has been locked in a cycle of escalating tension that has seen Pyongyang threaten missile and nuclear strikes against the United States and South Korea in response to UN sanctions and joint military drills.
On Wednesday, it went a step further by blocking access to a key joint industrial zone with South Korea – the Kaesong complex – which is the one surviving example of inter-Korean cooperation.
"We have asked for a (UN) Security Council meeting and in particular we ask the Chinese who have power over North Korea to intervene," Fabius said.
Beijing has been Pyongyang's sole major ally for decades and is its biggest trading partner, providing key energy supplies to the poverty-stricken nation.
On Wednesday, China appealed for "calm and restraint" on the Korean peninsula, adding that Vice-minister Zhang Yesui had met North Korea's ambassador on Tuesday to express "serious concern" over the situation.