US official says US President Trump is prepared to ease sanctions on Iran and release its frozen assets in exchange for progress on the nuclear issue, reports Al Jazeera

Washington doubts Iran's promises after it violated the memorandum of understanding by firing on commercial ships. We need guarantees this time that Iran is serious and not just trying to get out of its difficult situation. Iran says it is flexible on the nuclear issue, but are far apart on who takes the first step. Traffic in the Strait of Hormuz is increasing, and the naval blockade and sanctions continue to undermine Iran's position. Our position is growing stronger, and President Trump is patient and committed to preventing Iran from acquiring a nuclear weapon.