A forum representing countries including the European Union member states, Saudi Arabia, Jordan, and Turkey on Monday called for an "immediate ceasefire" in Gaza and Lebanon.
The Union for the Mediterranean also urged Israel to cease unilateral measures undermining a two-state solution to the Israeli-Palestinian conflict as the Gaza war spills over across the Middle East.
In a press conference after their meeting in Barcelona, EU foreign policy chief Josep Borrell called for a political solution to the crisis that "every day drives more people to despair and sows the seeds of hatred that will wipe out entire generations".
The forum, which gathers the EU and other countries in the Mediterranean basin, said in a joint statement that an "immediate and permanent ceasefire" in Lebanon and Gaza is a "top priority".
They also urged Israel to stop actions such as building settlements in the occupied West Bank and attacking UN peacekeepers in Lebanon.
All parties must protect civilians and respect international humanitarian law, they added.
Hamas's unprecedented attack on Israel on October 7 last year triggered the Gaza war that has devastated the Palestinian territory and sucked in Iran-backed groups across the Middle East.
Israel launched a ground offensive in Lebanon at the end of last month after escalating cross-border fire with Hamas ally Hezbollah and has exchanged direct fire with arch-enemy Iran.
Borrell said that Israel must show proportionality in its response and that the military escalation in Lebanon "has crossed all red lines".
He earlier condemned Israel's "unacceptable attacks" on UN peacekeepers in Lebanon.
Israeli Prime Minister Benjamin Netanyahu has said Hezbollah is using the peacekeeping force as "human shields" and called on it to withdraw.
Monday's gathering in Barcelona took place without Israeli representation for the second year running.