US President Donald Trump warned Iran over its imminent breach of a uranium enrichment cap.
Speaking to reporters in New Jersey, Mr Trump said Iran better be careful because you enrich for one reason. He said he won't tell Iran what that reason is.
US Secretary of State Mike Pompeo, earlier said Iran will face further sanctions
in response to the expected breach of the cap set by an endangered nuclear deal reached with international powers but from which the United States withdrew last year.
The top US diplomat said that Iran's latest expansion of its nuclear program will lead to further isolation and sanctions.