Poland has stopped allowing North Korean workers into the country as part of broader efforts to punish Pyongyang for its nuclear and missile programs, a South Korean government official said Tuesday.

Cho June-hyuck, spokesman of Seoul's foreign ministry, confirmed a report by the Washington-based Voice of America that Poland has not received any North Korean workers since the communist country conducted its fourth nuclear test in January.

"The issue of overseas North Korean workers has increasingly caused concern within the international community from the perspective of human rights abuses and the flow of money into the North," Cho said during a regular press briefing. "The Polish government also decided early this year to halt the issuance of new visas to North Korean workers."

North Korea is believed to have more than 50,000 workers stationed in some 50 countries, including China and Russia, to earn money for its cash-strapped regime.

Several hundred North Koreans are currently estimated to be working in Poland. Under the new measure, they will not be allowed to renew their visas.

Cho said other countries in Africa, the Middle East and Europe have also taken steps to reduce the number of North Korean laborers they receive by cracking down on illegal immigrants and not renewing work contracts.

"Our government takes note of such efforts by the international community to address the issue of overseas North Korean workers and plans to continue to seek possible steps in cooperation with the international community," he said.

The U.N. Security Council in March adopted tough sanctions against Pyongyang to punish the regime for its nuclear test and banned long-range rocket launch in February.

The sanctions, along with those imposed separately by South Korea, the United States and other nations, are designed to starve Pyongyang of the resources it needs to develop its nuclear and missile programs. (Yonhap)