According to the assessment of a nation in the Group of Seven, China is unlikely to be pleased with the alliance between Russia and North Korea, the people said. The upcoming G-20 summit in Rio will be an opportunity to push the issue with Beijing, said the people, without providing more specifics.

SEOUL, South Korea (AP) — North Korea ratified a major defense treaty with Russia stipulating mutual military aid, the North’s state media reported Tuesday, as the U.S., South Korea and Ukraine say North Korea has sent thousands of troops to Russia to support its war against Ukraine.

SEOUL, Nov 12 (Reuters) - North Korea has ratified a mutual defence treaty with Russia signed by the two countries' leaders in June, which calls for each side to come to the other's aid in case of an armed attack, state media KCNA said on Tuesday.

North Korean troops have begun engaging in combat operations alongside Russian forces, the U.S. State Department said on Tuesday, expressing concern that Russia had turned to North Korea for soldiers to fight in its war with Ukraine.

Russian soldiers have been filmed giving North Korean troops battlefield training and language lessons, with some of Kim Jong-un’s men picking up swear words.

"Today I can confirm that over 10,000 (North Korean) soldiers have been sent to eastern Russia, and most of them have moved to the far western Kursk Oblast, where they have begun engaging in combat operations with Russian forces,