Speaking to reporters on Air Force One after talks in Beijing with Chinese President Xi Jinping, Trump said the two sides had agreed Tehran could not be allowed to have a nuclear weapon and must reopen the Strait of Hormuz, which it is currently blocking, prompting a rise in world oil prices.
The two most populous states are in a political battle poised to have a major impact on the balance of power in Washington DC.
Lambertina Galeana Marín is suspected of having been behind the disappearance of key CCTV footage.
Police are searching for the suspect after a gunman opened fire in a classroom, killing two and injuring nine others in Providence, Rhode Island.