ATHENS — French President Emmanuel Macron signed a renewed bilateral strategic defence agreement with Greece during an official visit to Athens and called on European Union member states to activate the mutual assistance clause of the EU treaty following a drone attack on a British airbase in Cyprus on 28 February. Macron urged the invocation of article 42, paragraph 7 of the EU treaty, which he described as stronger than article 5 of the NATO treaty.

France, Greece, Spain, Italy, the Netherlands and Portugal sent military assistance to Cyprus after the drone attack on the British airbase. Macron argued that Europe was better off boosting its own security than relying on the U.S. administration under Donald Trump.

"On article 42, paragraph 7, it's not just words. We know that for us, it is clear and there is no room for interpretation or ambiguity," Macron said.

"I really believe this US approach will last," Macron said. "There is now a doubt on article 5, not put on the table by the Europeans but by the US president."

"It is clearly a de facto weakening of the Nato alliance," he said, adding: "I am a strong believer in the European pillar of Nato and my view is that we should strengthen this European pillar."

"We should not underestimate that this is a unique moment where a US president, a Russian president and a Chinese president are dead against the Europeans," Macron said.

Greek Prime Minister Kyriakos Mitsotakis backed the call to activate the clause. "What we did in Cyprus was a gamechanger," Mitsotakis said. "We have a mutual assistance clause in our treaties and this is our European responsibility." He added: "Doing so would be tantamount to a political statement that the EU did not only rely on Nato, and would be also good for Nato."

European Council President António Costa said work was under way on procedures for invoking the clause. "We are designing the handbook [on] how to use this mutual assistance clause," Costa said.

The visit, Macron's third official trip to Greece before he leaves office next year, also produced nine accords signed on Saturday between France and Greece to increase cooperation in areas including scientific research and nuclear technology. Macron vowed that France would stand by Greece if it ever came under attack from Turkey.