The U.S. Secretary of State Antony Blinken has warned that Iran and Hezbollah may launch an attack on Israel within the next 24 to 48 hours. This urgent report from the American publication Axios was published on Monday amid growing fears of a regional war in the Middle East. Iran and Hezbollah have vowed to avenge the killings of two of their senior leaders who were killed last week.

According to three anonymous sources, Axios reports that during a conference call with G7 colleagues, Blinken informed them that Iran and Hezbollah could initiate an attack on Israel as early as Monday. The sources stated that Blinken emphasized the U.S. belief that both Iran and Hezbollah would retaliate. The U.S. Secretary of State added that Washington “does not know the exact timing of the attacks” or the form they might take. He urged his G7 colleagues to join efforts to prevent escalation by applying diplomatic pressure on the involved parties, including Iran and Hezbollah.

The G7, which also includes Canada, France, Germany, Italy, Japan, and the United Kingdom, issued a statement on Monday expressing “deep concern over the heightened level of tension in the Middle East” and called for restraint from all sides, insisting that “no nation will benefit from further escalation.”

Following the killing of Hamas leader Ismail Haniyeh on July 31, the U.S. has deployed additional military forces to the Middle East in anticipation of retaliatory attacks. They insist that this deployment is “defensive.” According to reports, the head of the U.S. Central Command, General Michael Kurilla, is set to arrive in Israel on Monday to “complete preparations” with the Israeli military “in advance of a possible attack.”

Israeli Defense Minister Yoav Gallant warned, saying, “If they dare to attack us, they will pay a high price.” The nearly 10-month-long war in Gaza between Israel and Hamas has led to regular low-level conflicts between Israel, Iran, Hezbollah, and other groups in the region allied with Tehran.

It is broadly believed that neither side is ready for total war; however, the heightened tensions increase the risk of escalation. The list of countries advising their citizens to leave Lebanon immediately grew on Monday after warnings from the U.S. and many European governments. Japan, Saudi Arabia, and France are among the latest countries urging their citizens to leave the country while commercial flights are still operating.

In a “very unstable security situation,” the French Foreign Ministry urged its citizens to avoid travel to Lebanon and suggested that those already in the country leave “as quickly as possible.”