By Gram Slattery, Phil Stewart, Steve Holland and Jonathan Landay WASHINGTON (Reuters) -Roughly one month ago, from the stage at an investment forum in Saudi Arabia, U.S. President Donald Trump issued a warning to Iran that would prove prophetic.

Press secretary Karoline Leavitt says the US president believes there is a "substantial chance of negotiations" with Iran "in the near future".

The Iran-Israel conflict has entered its seventh day with no signs of de-escalation. Israel has launched strikes on Tehran, reportedly targeting Ayatollah Khamenei's hideout. US President Donald Trump warned of 'big' action next week,