Blasts have been heard in Tehran and sirens have sounded in Israel as US president convenes National Security Council.

U.S. President Donald Trump on Monday night cut short his participation at the G7 summit to leave Alberta, Canada, and returned to Washington, D.C., to focus on the conflict between Israel and Iran. French President Emmanual Macron announced Trump had made a cease-fire offer between the two countries.

U.S. President Donald Trump said his early departure from the G7 summit was owed to "much bigger" things than planning a ceasefire between Tel Aviv and Tehran. G7 leaders affirmed unified support for Israel and condemned Iran for being the "principal source of regional instability and terror.