President Trump slammed China on Thursday over the country’s reported illegal oil sales to North Korea, saying they’ve been caught “RED HANDED” and warning such incidents could diminish the odds of a “friendly solution” for Pyongyang.

“Caught RED HANDED - very disappointed that China is allowing oil to go into North Korea. There will never be a friendly solution to the North Korea problem if this continues to happen!” Trump tweeted, while on a holiday break in Florida.

U.S. spy satellites reportedly captured photos of Chinese ships illegally selling oil to North Korean boats some 30 times since October.

REPORT: CHINA SPOTTED ILLEGALLY SELLING OIL TO N. KOREA

Satellite images released by the U.S. Department of Treasury appeared to show vessels from both countries illegally trading oil in the West Sea, The Chosun Ilbo reported Tuesday, citing South Korean government sources.

North Korea was barred in September by the United Nations Security Council from importing natural gas and had its crude oil imports capped in response to Kim Jong Un’s nuclear missile program.

The U.S. Treasury in November also sanctioned North Korea’s Maritime Administration and its transport ministry, in addition to six North Korean shipping and trading companies and 20 of their vessels, in an effort to block the rogue regime’s transportation networks.

The satellite images appear to identify the ships. One of them — Rye Song Gang 1, seen “connected to a Chinese vessel” — was included in the Nov. 21 sanctions as a vessel of Korea Kumbyol Trading Company possibly transferring oil to evade sanctions.

While Russia exports some oil to North Korea, China is the main source of oil for the rogue nation, according to Reuters. However, the country’s records reportedly showed it exported no oil products to the North during the month of November. It was reportedly the second consecutive month China didn't export diesel or gasoline to North Korea.

NORTH KOREA CALLS UN SANCTIONS 'AN ACT OF WAR,' 'RIGGED UP BY THE US'

A government source told the South Korean newspaper that, "We need to focus on the fact that the illicit trade started after a UN Security Council resolution in September drastically capped North Korea's imports of refined petroleum products."

Chinese foreign ministry spokeswoman Hua Chunying said she had no information following Chosun’s report, but said “the Chinese government has been completely and strictly enforcing Security Council resolutions” aimed at discouraging North Korea from developing nuclear and missile technology.

Fox News’ Nicolle Darrah and The Associated Press contributed to this report.