US Secretary of State Antony Blinken told his counterparts from the G7 countries on Sunday that an attack by Iran and Hezbollah against Israel could start as early as Monday, three sources briefed on the call tell Axios, the latter reports. Blinken convened the conference call to coordinate with close US allies and try to generate last-minute diplomatic pressure on Iran and Hezbollah to minimize their retaliation as much as possible. He stressed that limiting the impact of their strikes is the best chance to prevent all-out war. Iran and its Lebanese ally Hezbollah have vowed to respond to the assassinations by Israel of Hamas political leader Ismail Haniyeh in Tehran and Hezbollah military commander Fuad Shukr in Beirut. The secretary of state told his counterparts the US is making efforts to break the escalatory cycle by trying to limit the attacks by Iran and Hezbollah as much as possible and then restrain the Israeli response. One source said Blinken sounded frustrated when he briefed the ministers on recent talks with Israel over a Gaza hostage and ceasefire deal. Blinken said the US administration felt it was "close to a breakthrough" before the assassination in Tehran. Now a deal is needed more than ever, he added.