US President Donald Trump said that China was elling oil to North Korea, stating that such moves would prevent "a friendly solution" to the crisis over Pyongyangs nuclear program. "Caught red handed - very disappointed that China is allowing oil to go into North Korea," Trump tweeted on Thursday. China rejected the accusations on Friday, stressing that China did not violate UN resolutions and had looked into the report of a Chinese ship transferring oil to a North Korean vessel and found it to be inaccurate. An official of the US State Department said the US government was aware of vessels engaged in such activity involving refined petroleum and coal, according to Reuters. “We have evidence that some of the vessels engaged in these activities are owned by companies in several countries, including China,” the official said, speaking on condition of anonymity. Chinese foreign ministry spokeswoman Hua Chunying said, "The recent series of reports on this situation do not conform with the facts." “China has always implemented UN Security Council resolutions pertaining to North Korea in their entirety and fulfils its international obligations. We never allow Chinese companies and citizens to violate the resolutions,” Hua added. “The Chinese side has conducted immediate investigation. In reality, the ship in question has, since August, not docked at a Chinese port and there is no record of it entering or leaving a Chinese port,” Hua said. South Korea said on Friday it had seized a Hong Kong-flagged ship suspected of transferring oil to North Korea in defiance of the sanctions. A senior South Korean foreign ministry official said the ship, the Lighthouse Winmore, was seized when it arrived at a South Korean port in late November. “It’s unclear how much oil the ship had transferred to North Korea for how long and on how many occasions, but it clearly showed North Korea is engaged in evading the sanctions,” an official told Reuters. China’s foreign ministry spokeswoman said she did not have any information about the matter.