Hours after international sanctions linked to Iran’s nuclear programme were officially lifted, US President Barack Obama’s administration imposed new sanctions on Iran yesterday because of its development of ballistic missiles.

Under the new sanctions, the US treasury has included 11 Iranian companies and 5 individuals on a black list because of their involvement in the ballistic missile programme and the purchase of components for these missiles. These entities are prohibited from using the banking system in the United States.

At the same time, Washington and Tehran announced an unprecedented exchange of four American-Iranians freed by Tehran with seven Iranians who were released and pardoned by the United States. A fifth American was also released.

US media has widely welcomed the prisoner exchange deal after negotiations indirectly linked to the completion of the nuclear deal. Officials at the American administration denied that sanctions imposed on Iran because of ballistic missiles were delayed for political reasons.

While the Iranian President Hassan Rouhani promised a “suitable response” to the new sanctions, President Obama stressed that Washington would remain firm in the face of Iranian threats to the countries of the region. Obama also said in a speech at the White House that “the implementation of the nuclear agreement began alongside the reunion of American families”, alluding to “the historical development that was achieved through diplomacy without a new war in the Middle East.” He believes that “this proves the possibility of adopting strength, wisdom and patience”, and praised the role of Switzerland in the negotiations with Iran.

The Acting Under Secretary for Terrorism and Financial Intelligence Adam Szubin said that “Iran’s ballistic missile program poses a significant threat to regional and global security, and Iran will continue to be subject to international sanctions”.

In Tehran, Rouhani attributed his country’s success in reaching a nuclear agreement to the “support” of the Supreme Leader Ali Khamenei in his first speech after the announcement of “the official day of the agreement’s implementation” and added that the nuclear agreement is “a national achievement” that serves the people and national interests.