sentences:  Iran and North Korea pledge cooperation in educational, scientific, and cultural spheres.Some media reports claim this cooperation extends to nuclear cooperation, though official U.S. government publications and academic studies have disputed this.The United States has been greatly concerned by North Korea's arms deals with Iran, which started during the 1980s with North Korea acting as a third party in arms deals between the Communist bloc and Iran, as well as selling domestically produced weapons to Iran, and North Korea continues selling missiles to Iran.