United Nations — North Korea has violated sanctions by importing more oil than is permitted by the United Nations, by using illicit ship-to-ship transfers on the high seas, the U.S. tells the U.N. in a new still-unpublished report, obtained by CBS News. The report, along with 28 images, was submitted to the U.N. sanctions committee on Tuesday, and Security Council members have been told that they have until next Tuesday, June 18 at 3 p.m. to submit any changes.

What is most unusual for one of the many annual and mid-term reports on North Korea's sanctions violations, this report, submitted by the U.S., is supported by 25 other countries, including Western powers, as well as Japan and South Korea, and calls for action by the Security Council.

The U.S. Mission to the U.N. submitted the report to the chair of the U.N. sanctions committee, Germany's Ambassador Christoph Heusgen, with a letter dated June 11, 2019, and signed by 24 nations, including the U.S., France and Germany, along with a note from the chair stating that the Republic of Korea and the United Kingdom also co-sponsored the letter.

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The note by the chair of the sanctions committee to Security Council members says that the report details "observations of illicit imports of refined petroleum by the Democratic People's Republic of Korea [or DPRK, the official name of North Korea], which combined with the reported imports, would result in the aggregate amount of refined petroleum imported into the DPRK exceeding the cap of 500,000 barrels," established under a 2017 U.N. Security Council resolution.

In the report, the U.S. and Japan documented at least eight instances of illicit, sanctions-busting transfers and the graphs show satellite images of several of these. One diplomat said that some of the language in the graphs may need to be changed to conform to the name of the seas in which the vessels were located.

Images obtained by CBS News from a yet-to-be published report from the United States sent to the United Nations.

The letter from the United States Mission to the U.N. to the chair of the sanctions committee suggests three actions:

Inform all 193 U.N. member states and the general public that North Korea has breached the annual quota and order an "immediate halt to all transfers of such products." Update the website to show that the 2019 quota for refined petroleum imports has been filled. Call on all nations to "immediately exercise enhanced vigilance" to prevent North Korea from procuring additional refined petroleum products and "prevent illicit ship-to-ship transfers."

"The United States and its partners remain gravely concerned about the degree of U.N. Security Council resolution violations that are occurring," the U.S. cover letter states.

North Korea has long flouted U.N. sanctions, but enforcement has become tougher every year.

Hagar Hajjar Chemali, a former spokesperson at the U.S. Treasury Department and U.S. Mission to the U.N. told CBS News North Korea has sophisticated sanctions evasion tactics to circumvent international sanctions.

"It doesn't mean the sanctions aren't having an effect, but it does mean that the North Korean regime is good at finding workarounds through illicit ship-to-ship transfers, deceptive business practices, joint ventures, and exporting North Korean labor, among other means," Chemali said, adding that the most important element of sanctions is their enforcement.

The context of the report is a stalemate in negotiations that has occurred since the second Trump-Kim summit, in Hanoi, failed to produce an agreement on denuclearization. In addition, the U.S. seized a North Korean cargo ship for violating international sanctions, after North Korea fired short-range missiles for the second time in a week.

This week, President Trump reported he received a "beautiful" letter from North Korean leader Kim Jong Un, but declined Wednesday to discuss its contents.