WASHINGTON (Reuters) - The United States said Thursday it is working to cut off revenue streams to North Korea by targeting remittances from its overseas workers, after recent nuclear and missile tests by Pyongyang. Deputy Secretary of State Antony Blinken told a House of Representatives hearing that the United States is working “relentlessly” to get countries to cut off businesses sending money back to North Korea.  He also said Washington is working to encourage the sending home of North Korean diplomats not engaged in diplomatic activity and to make sure that people did not travel to North Korea, including for the May 6 congress of the ruling Workers Party.     “What we are focused on, besides the implementation of the (U.N.) Security Council resolutions, is relentlessly building pressure on North Korea, working principally with our key allies Japan and (South) Korea,” Blinken said.  “We are working in various ways to cut off all the revenues going to the regime. For example, they have ... overseas workers whose remittances are not going back to their families, but are going to the regime. We’re working to cut those off.”     Estimates of North Korean workers abroad vary widely but a study by South Korea’s state-run Korea Institute for National Unification put the number as high as 150,000, primarily in China and Russia, sending back as much as $900 million annually. North Koreans are known to work abroad in restaurants and on construction sites, and also as doctors.     The United States is also working to make sure North Korean officials are not invited to travel abroad and to ensure North Korean ships and aircraft are not allowed to dock or land in other countries, Blinken said. The senior U.S. diplomat for Asia, assistant secretary of state for East Asia, Danny Russel, said last week that another North Korean nuclear test could trigger new sanctions including an effort to choke off hard currency earnings by its overseas workers abroad. North Korea has conducted a series of missile launches, in violation of U.N. resolutions in the run-up to the Party congress and experts believe it may conduct a new nuclear test before this convenes.     
U.S. says working to cut off North Korean remittances