North Korea is building its largest-ever warship ever — possibly more than double the size of anything in its existing fleet.

The construction marks the first ever bridge for cars and motor vehicles crossing between Russia and North Korea and is a “significant milestone” in the relationship between Moscow and Pyongyang, Russian prime minister Mikhail Mishustin said on Wednesday as he attended the groundbreaking ceremony in a video conference.

The two countries have vowed to expand bilateral relations after North Korea sent troops and weapons in support of Russia’s war against Ukraine.