SEOUL (Reuters) -North Korea enabled Russia to increase missile attacks against critical Ukrainian civilian infrastructure and supplied more than 20,000 containers of munitions, according to a report by the Multilateral Sanctions Monitoring Team, a group comprising 11 UN members.

The group, launched in October last year to monitor U.N. sanctions against North Korea after a Security Council panel was scrapped by Russia and China, also said Moscow helped the North improve missile performance in return by supplying data.

As many as nine million rounds of artillery and rocket launcher ammunition was shipped from North Korea to Russia by Russian cargo vessels as part of military cooperation between the two countries in violation of U.N. sanctions, it said.

"At least for the foreseeable future, North Korea and Russia intend to continue and further deepen their military cooperation in contravention of relevant U.N. Security Council resolutions," the group said in its first report.

The group comprises the United States, South Korea, Japan, and eight U.N. member states and was introduced after Russia vetoed the renewal of a U.N. panel that enforced sanctions over North Korea's nuclear and missile programs for 15 years.

China abstained from the vote.

North Korea's help "contributed to Moscow's ability to increase its missile attacks against Ukrainian cities including targeted strikes against critical civilian infrastructure," the report said.

Since it started shipping ammunition to Russia in September 2023, North Korea has transferred at least 100 ballistic missiles, self-propelled artillery, long-range multiple rocket launchers and munitions for them, it said.

Russia in return "supported North Korea's ballistic missile programs by providing data feedback ... leading to improvements in missile guidance performance," it said. Moscow also provided air defense equipment and anti-aircraft missiles as well as electronics warfare systems to North Korea, it said.

After months of silence, North Korea and Russia confirmed in April Pyongyang had deployed troops to fight for Russia in the war in Ukraine as part of a comprehensive strategic partnership treaty their leaders signed last year.

The treaty includes a mutual defense pact. The two countries have not explicitly confirmed the exchange of military equipment or technology.

(Reporting by Jack Kim; Editing by Toby Chopra)