China has said the root cause of North Korean missile launches is friction with the United States and South Korea.
It comes as China faces criticism that it is not doing enough to pressure North Korea to drop its nuclear programme.
North Korea fired a banned ballistic missile on Sunday, its first test since US President Donald Trump took office.
The missile, launched as Mr Trump hosted Japanese Prime Minister Shinzo Abe in Florida, is believed to have flown about 500 kilometres (300 miles) before splashing down in international waters.
Foreign ministry spokesman Geng Shuang said China opposed the launch, which violated UN Security Council resolutions that call for an end to North Korea's nuclear and missile tests.
China is North Korea's largest source of trade and aid, and Mr Trump has complained that Beijing is not doing enough to pressure it.
Beijing counters that its influence is overstated and suggests that Washington's refusal to talk directly to North Korea is impeding progress towards a solution.
"The root cause of the (North Korea) nuclear missile issue is its differences with the US and South Korea," Mr Geng told reporters.
Mr Geng said China, a permanent member of the UN Security Council, has been "completely and comprehensively" implementing Security Council resolutions on the nuclear issue.
He said Beijing "has been striving for a settlement of the Korean Peninsula issue by proactively engaging in mediation and promoting peace talks".
Mr Geng urged all sides to refrain from provocative action and said China would continue participating in Security Council discussions in a constructive and responsible way.
He added that China has long been encouraging Seoul and Washington to have a dialogue with North Korea.