Answer :
The Port of Vladivostok is on the Sea of Japan and located near Russia's border with China. Russia's port city of Murmansk is located in Murmansk Oblast in the Northwest of Russia.
The port that is on the Sea of Japan and is closest to the Russian-Chinese border is Vladivostok. Vladivostok is a city whose economy is based on and around the port and it is of extremely big geostrategic and economic value to Russia because its location is excellent and is in close proximity to countries that are strong economies and from which Russia has a huge income.
The port city of Murmansk is located in the northwest part of Russia, in the Murmansk oblast, on the Kola peninsula. It is a port of big importance because it is in the Arctic circle, and Russia has very big interest of the area about the natural resources in there, so Murmansk is most often the base for any exploration of the Arctic.