“The United States is concerned by Russia's growing relationship with North Korea and by what technology the two countries may be exchanging, the top U.S. arms control official said on Wednesday. Speaking to Reuters in Bucharest at a forum on preventing nuclear and radiological terrorism, Under Secretary of State Bonnie Jenkins said the U.S. was working with Japan and South Korea to address those countries' concerns about North Korea. She echoed remarks by U.S. Secretary of State Antony Blinken who said in Brussels on Wednesday that Moscow's relationship with Pyongyang was a two-way street, and that there was deep concern about what Russia was or may be doing to strengthen "North Korea's capacity", including its nuclear capacity.”