The swift response to Trump's Tuesday tweet from Beijing's foreign ministry comes at a time when about 70,000-80,000 North Korean forced laborers continue to be employed in Chinese industries, according to South Korean researchers.
Chinese foreign ministry spokesman Geng Shuang said Wednesday China should not be so easily discredited, South Korean news service Newsis reported.
"China has worked tirelessly to realize peace on the Korean peninsula, and has an important and constructive role in the process," Geng said, referring to Trump's tweet. "We have worked continuously on North Korea sanctions."
Geng also said China was "strictly enforcing" United Nations Security Council sanctions resolutions against North Korea.
"Relevant countries must take responsibility for looking at the nuclear issue in a large framework and play a role" within the framework, the Chinese government spokesman said.
On Tuesday Trump tweeted, "While I greatly appreciate the efforts of President Xi & China to help with North Korea, it has not worked out. At least I know China tried!"
While I greatly appreciate the efforts of President Xi & China to help with North Korea, it has not worked out. At least I know China tried!— Donald J. Trump (@realDonaldTrump) June 20, 2017
China suspended all North Korea coal imports in February, and fear has been rising in North Korea that crude oil supplies could be reduced, which may have led to a spike in North Korea gasoline prices in May and June.
China, however, may have been less vigilant regarding the employment of North Korean forced laborers within its borders.
Oh Kyung-seop, a researcher with South Korea's Korea Institute for National Unification, said Wednesday as many as 80,000 North Koreans work in low-wage jobs in Chinese industries that benefit from cheap labor, Yonhap reported.
Yeom Seung-cheol of Unification Media Group said at the same seminar in Seoul on Wednesday that North Korean laborers in China make a monthly wage of $200-300, but North Korean authorities collect two-thirds of the income earned.
Workers are not insured, and one North Korean worker in China "used a year's worth of savings" for the removal of his appendix, Yeom said.
Yeom said he collected some of his interviews from Christian missionaries working in China.