WASHINGTON, Feb. 6 (Xinhua) -- The United States is "disappointed" that Poland's president has signed legislation that would impose criminal penalties for attributing Nazi crimes to the Polish state, said U.S. Secretary of State Rex Tillerson on Tuesday.

"Enactment of this law adversely affects freedom of speech and academic inquiry," said Tillerson in a statement released by the U.S. State Department.

Polish President Andrzej Duda signed a highly controversial anti-defamation bill on Tuesday, which proposes to jail or fine a person who blames Poland or the Poles for Nazi crimes against humanity which were committed in Nazi-occupied Poland during World War II.

The bill also prohibits phrases such as "Polish death camps."

"Such historical inaccuracies affect Poland ... and must be combatted in ways that protect fundamental freedoms," said the U.S. top diplomat.

During a televised address on Tuesday, Duda justified his decision by emphasizing that "we need to protect the good name of the Polish people and Poland both."

The law still needs verification by the Constitutional Court, in order to ensure its compatibility with the constitution.

The new legislation has already sparked an uproar in Israel.

About six million Jews were killed by the Nazis in World War II, and many of them in the death camp of Auschwitz and other death camps in Poland.