Speaking at a diplomatic seminar in Lisbon organised by Portugal’s foreign ministry, Borrell said that “the seeds of hate are being sown.”

“If this tragedy doesn’t end soon, I fear that all of the Middle East will see itself engulfed in flames,” he added.

His stark warning comes a day after Saleh al-Arouri, a senior Hamas official and the organisation’s second-in-command, was killed in an Israeli airstrike in the Lebanese capital Beirut.

Israel has not claimed responsibility for the assassination, but an adviser to Israeli Prime Minister Benjamin Netanyahu said on Wednesday that whoever was responsible had executed a “surgical strike against the Hamas leadership.”

The assassination of al-Arouri, one of the founders of Hamas’ military wing, on Lebanese soil presents a significant threat of regional escalation that could pull in the Lebanese militant group Hezbollah, who are Tehran-backed allies of Hamas.

Brewing tensions in the Red Sea are also stoking fears of a regional escalation. A raft of attacks on commercial vessels by the Iran-backed Houthi rebel group, which controls a part of Yemen, has prompted the US to deploy a naval mission to the region.

The US Navy killed 10 Houthi militants as they attempted to sabotage a Danish-operated ship on Monday. Iran has responded by moving a warship into the Red Sea, heightening fears of a further escalation.

‘No unanimous position weakens EU’

During Wednesday’s keynote speech, Borrell also lamented that the European Union had not been able to unanimously agree on calling for a humanitarian ceasefire in Gaza. More than 20,000 people are expected to have lost their lives in the conflict that erupted following Hamas’ deadly attack on Israel on 7 October.

“We have not been able within the European Council to come to a unanimous position calling for a ceasefire,” Borrell explained. “On the contrary, we have limited ourselves to a bare-bones agreement, calling for humanitarian pauses and an increase in aid for victims.”

“There is no unanimous solution or position, and that weakens us (the EU),” he added.

A UN General Assembly resolution calling for a humanitarian ceasefire in Gaza voted on in December secured the backing of a majority of the EU’s 27 member states. Austria and the Czech Republic, both staunch allies of Israel, were the only countries to vote against the resolution and have consistently expressed fears that a joint EU call for a ceasefire would undermine Israeli efforts to eradicate Hamas.

The persistence of the war has seen countries gravitating towards calls for further restraint, with a major shift in rhetoric seen by EU nations such as France. Other nations including Belgium, Spain, and Ireland have been vocal advocates of a ceasefire in Gaza from the early stages of the conflict.

Borrell has previously suggested that a series of permanent pauses in hostilities should “evolve” into a permanent ceasefire in Gaza.

Comparing the European bloc’s firm stance and solid support to Kyiv following Russia’s invasion of Ukraine, Borrell warned that the accusation of Europe’s double standards was “taking on form.”

“The clear and firm European position on the war in Ukraine is not shared by many countries in the world, who immediately accuse us of having principles that are geometrically unaligned – what they call double standards,” he said.

“And I think that unless we close our eyes and our ears, it’s difficult not to face up to this contradiction,” he added.

Borrell also stated that the fact that EU countries are having to consistently call on Israel to respect international humanitarian law in its assault on the Gaza Strip suggests that it is not acting within the boundaries of the law.