Tokyo, Oct 25 (IANS): Japan is preparing a plan to sanction foreign companies that trade or facilitate capital inflows to North Korea as punishment for their ongoing testing of missiles and nuclear weapons.

This blacklist would mainly affect Chinese companies - especially those who operate on the border with North Korea - that are helping the country to evade UN sanctions enforced this year in response to its weapons tests, a Japanese government source told Kyodo News on Tuesday.

Tokyo expects protests from Beijing over the move, and so will carefully examine the extent and timing of the new unilateral sanctions while continuing to participate in talks at the UN on proposals for additional sanctions in response to Pyongyang's nuclear test on September 9, the source said.

The plan would also affect companies employing North Korean workers, who are usually sent to work in third countries and are strictly controlled and forced to give up the majority of their wages in foreign currency to Pyongyang, EFE news reported.

These "exchange programmes" - implemented by countries like Qatar for the construction of facilities related to the hosting of the 2022 FIFA World Cup - have been repeatedly denounced by human rights organisations for the appalling conditions in which North Korean employees work without receiving any compensation.

Tokyo sanctions would involve freezing all assets that these companies have in Japan and banning Japanese companies from doing business with them.

The plan is similar to that recently adopted by the US, which decided to investigate several Chinese companies operating in border regions with North Korea after it sanctioned a firm in the northeast province of Liaoning for allegedly helping to finance Pyongyang's nuclear programme.