China called for restraint Monday after last week North Korea claimed it successfully test-launched a submarine-based ballistic missile.
"We hope that all relevant parties can do more to ease tensions and jointly uphold peace and stability on the Korean Peninsula," China's foreign ministry spokeswoman Hua Chunying told journalists.
He added that the current situation on the Korean Peninsula is complex and "very sensitive".
According to North Korean state media, leader Kim Jong-un oversaw the test-firing from an offshore location. If the launch is confirmed, it would be a significant step-up in the North’s missile technology.
UN resolutions banned North Korea from conducting ballistic missile tests.
The US State Department said the recent missile test violated UN resolutions.
South Korea also expressed concerns about the North’s new test-firing.