China exported no oil to North Korea in the first four months of this year. The North depends on China to supply it with between 520,000 and 570,000 tons of crude oil per year.
Citing Chinese customs data, the Beijing office of the Korea Trade-Investment Promotion Agency said China's crude oil exports to North Korea from January to April of this year amounted to a rare zero.
There have been one- to two-months suspensions before due to pipe maintenance, but the last time Beijing halted crude exports to North Korea for four months was in 2009, after Pyongyang conducted its second nuclear test.
China is applying various kinds of pressure on North Korea to prevent it from conducting another nuclear test, but there are suspicions that the oil exports have in fact continued clandestinely.