Three men were arrested in Moldova earlier this year for attempting to sell radioactive materials to an undercover police officer posing as a middleman for the Islamic State group.
Pakistan and the United States reportedly have been holding discussions about Islamabad’s possible admission into the Nuclear Suppliers Group.
The fourth and final nuclear security summit will take place next March 31-April 1 in Washington, D.C., the White House said Aug. 10.
India and the United States reached what President Barack Obama described as a “breakthrough understanding” on two issues that have held up nuclear trade between the two countries.
Russia did not attend a planning session held in Washington in late October for the 2016 nuclear security summit, casting doubt on its participation in the summit.