Madrid - A Spanish prime minister considered declaring a war against neighbouring Portugal to stem the spread of communism in the final year of General Francisco Franco's 36-year dictatorship, the daily El Pais reported Monday.

Carlos Arias Navarro, Franco's last prime minister, met with US deputy secretary of state Robert Ingersoll in Jerusalem in 1975, the daily quoted US national archives as revealing.

Arias Navarro expressed concern over the establishment of a leftist government in Portugal following the 1974 Carnation Revolution, which toppled prime minister Marcelo Caetano's authoritarian government.

"Spain would be willing to fight the anti-communist combat alone if necessary," Ingersoll wrote to then secretary of state Henry Kissinger.

Arias Navarro nevertheless sought "the cooperation and understanding of friends" such as the United States in case a war broke out, Ingersoll added.

Franco's death in 1975 put an end to his right-wing dictatorship, and Spain launched a transition into democracy. (dpa)