In a photo taken on Feb. 8, 2020, people bow before the statues of late North Korean leaders Kim Il-sung and Kim Jong-il on Mansu Hill, to mark the 72nd anniversary of the founding of Korean People's Army in Pyongyang. AFP

North Korea continued to enhance its nuclear and ballistic missile programs last year in breach of United Nations sanctions, according to a confidential U.N. report seen by Reuters on Monday.

The country also illicitly imported refined petroleum and exported some $370 million worth of coal with the help of Chinese barges, the report added.

The 67-page report to the U.N. Security Council North Korea sanctions committee, which is due to be made public next month, comes as the United States tries to revive stalled denuclearization talks with North Korea.

"In 2019, the Democratic People's Republic of Korea (DPRK) did not halt its illicit nuclear and ballistic missile programs, which it continued to enhance, in violation of Security Council resolutions," the independent U.N. sanctions monitors wrote.

"Despite its extensive indigenous capability it uses illicit external procurement for some components and technology."

North Korea has been subjected to U.N. sanctions since 2006. They have been strengthened by the 15-member Security Council over the years in a bid to cut off funding for Pyongyang's nuclear and ballistic missile programs.

SHIP-TO-SHIP TRANSFERS

The sanctions monitors said that in a fresh bid to evade sanctions, North Korea had started to export millions of tonnes of commodities - banned since 2017 - using barges.

"According to a Member State, the DPRK exported 3.7 million metric tons of coal between January and August 2019, with an estimated value of $370 million," the report said.

"According to the Member State, most DPRK coal exports, an estimated 2.8 million metric tons, were conducted via ship-to-ship transfers from DPRK-flagged vessels to Chinese local barges."

The unidentified member state told the monitors that barges had delivered coal directly to three ports in China's Hangzhou Bay and also to facilities along the Yangtze river.

The U.N. monitors also said a member state reported that North Korea had exported at least one million tonnes of sand from river dredging, worth at least $22 million, to Chinese ports.