The editorial is the Vatican's latest effort to rehabilitate the reputation of Pope Pius, whose reluctance to denounce the Nazis publicly prompted accusations of anti-Semitism and earned him the title "Hitler's Pope".

L'Osservatore dismissed such claims as a "radically false" characterisation of the pontiff's wartime record.

It quoted Morgenthau as saying that as early as Aug 1942, the US government "knew that the Nazis were planning to exterminate all the Jews of Europe".

In his diary, Morgenthau cited a telegram dated Aug 24, 1942, and passed on to the US State Department, that relayed a report of Hitler's plan to kill between 3.5 million and four million Jews, possibly using cyanide poison.

L'Osservatore, which is regarded as the semi-official mouthpiece of the Holy See, reproduced a copy of the telegram.

American officials had "dodged their grim responsibility, procrastinated when concrete rescue schemes were placed before them, and even suppressed information about