In a new report, the National Council of Resistance of Iran (NCRI) claims that Iran has received assistance from North Korea in constructing missile sites in Iran. The report states that Iran has served as permanent hosts to North Korean experts, who have helped Iran build underground facilities and tunnels to produce, store, and maintain missiles. These facilities and other Islamic Revolutionary Guard Corps (IRGC) missile sites are based on North Korean models and blueprints, according to NCRI. NCRI claims that there has been a frequent exchange of personnel between Iran and North Korea, with members of the IRGC Aerospace Force traveling to North Korea to exchange information with North Korean specialists. The report also presents evidence of work at 42 missile sites in Iran, twelve of which were previously undisclosed, according to NCRI. In addition, the report highlights the work done at the Semnan missile center, where NCRI states that missile work and nuclear research by the Organization of Defensive Innovation and Research (SPND) is integrated.

The U.S. Senate overwhelmingly passed a bipartisan bill to increase sanctions on Russia and Iran by a vote of 98-2.  The measure would impose mandatory sanctions on people involved in Iran's ballistic missile program and those who do business with them.  The bill would also apply terrorism sanctions on the Islamic Revolutionary Guard Corps (IRGC) and enforce an arms embargo. Separately, the bill targets Russia with new sanctions and codifies executive orders signed by former President Barack Obama in response to the 2014 annexation of Crimea and Russian support for seperatists operating in Eastern Ukraine. The legislation now moves to the House of Representatives.

The most recent International Atomic Energy Agency (IAEA) report on Iran's implementation of the nuclear deal noted that Iran's stock of low-enriched uranium was 79.8 kg as of May 27th and that the level of enrichment did not exceed 3.67 percent.  Iran's stock of heavy water reached 128.2 metric tons, close to the 130 ton limit under the nuclear deal, according to the report.  However, Iran is currently not producing heavy water after shutting down its heavy water production plant for maintenance.  The IAEA verified the shutdown on May 16.

Legislation that would impose new sanctions on Iran for its ballistic missile program, support for terrorism, and human rights violations won support from the Senate Foreign Relations Committee by a 18-3 vote and now will be considered by the full Senate. The sanctions bill has bi-partisan support and is not considered by most lawmakers to violate U.S. obligations under the Joint Comprehensive Plan of Action (JCPOA).