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.

Iran and Saudi Arabia have been in conflict with each other over influence in the West Asian and Muslim countries. However, the countries have been sharing mutual views on the Israel-Palestine conflict,

Tehran has asked Qatar, Saudi Arabia and Oman to press U.S. President Donald Trump to use his influence on Israel to agree to an immediate ceasefire with Iran in return for Tehran's flexibility in nuclear negotiations,