The Reuters news agency cited an anonymous US official telling it that the Pentagon had outlined the suspension option in an email looking at ways to punish NATO allies that steered clear of the US-Israeli war against Iran.

"Spain is a reliable member within NATO" which is fulfilling all its obligations, Sanchez told reporters in English during a visit to Cyprus for an EU summit.

"As a result, I am absolutely not worried," he said.

The Socialist leader added in Spanish: "we don't work on the basis of emails, we work off official documents and the position that the United States government has set out in this case."

There is no provision in the NATO treaty allowing for the suspension or expulsion of a member of the world's most powerful military alliance.

US President Donald Trump has repeatedly railed against NATO allies for refusing to join the war that engulfed the Middle East, saying he viewed it as a betrayal.

Some of them -- France, Spain and Italy -- did not allow US military aircraft deployed for the war to overfly their territories or to use bases.

Trump also tried, in vain, to get European NATO members to send warships to the Strait of Hormuz, the key waterway for Gulf energy exports, which Iran has effectively closed with military threats and attacks.

Washington's expectation that NATO members' facilities and territories should be available to the United States without question has added to strains within the alliance, which Trump has taken to calling a "paper tiger".

Italian Prime Minister Giorgia Meloni told reporters in Cyprus that "NATO must remain united. I believe it is a source of strength."

Sanchez said his government's stance was "absolute cooperation with allies, but always within the bounds of international law".

Sanchez has repeatedly found himself in Trump's crosshairs since the Republican president returned to office in January 2025.

Last year, he refused to agree to ramp up NATO defence spending to five percent of GDP as demanded by Trump, who then suggested expelling Spain from the alliance.

Sanchez condemned the US military intervention in Venezuela on January 3 that captured the South American country's strongman socialist president Nicolas Maduro and is a virulent critic of Washington's ally Israel.

NATO is to hold its next summit in Turkey on July 7-8.

burs-imm/giv