Josep Borrell said Saturday that a plan by Israel to evacuate more than one million people out of northern Gaza in a single day was «utterly impossible to implement».
Israel warned residents in the area to evacuate before an expected ground offensive against Palestinian Islamist organisation Hamas in retaliation for the deadliest attack in Israel's history.
«I am saying that, representing the official position of the European Union… (the evacuation plan) is utterly, utterly impossible to implement,» Borrell told a press conference in Beijing on the final day of a three-day diplomatic visit to China.
«To imagine that you could move one million people in 24 hours in a situation like Gaza can only be a humanitarian crisis,» he added.
EU chief Ursula von der Leyen had expressed support to Israeli Prime Minister Benjamin Netanyahu on Friday during a visit to the country.
«Europe stands with Israel,» said von der Leyen, adding that the country had «a duty to defend its citizens».
But Borrell's comments in Beijing showed the limits of that affirmation, saying that Israel was also obligated to follow international humanitarian law in the process of defending itself.
«The position is clear,» said Borrell. «We certainly defend the right of Israel to defend itself.»
«But, as any right, it has a limit.