Poland's president signed into law on Tuesday (local time) a bill that imposes jail terms for suggesting the country was complicit in the Holocaust, prompting sharp criticism from Israel and the United States.
Andrzej Duda said in a televised address the legislation would safeguard Poland's international reputation, but Israel called for amendments, saying the two countries had a "joint responsibility" to preserve the memory of the Holocaust.
The United States, a close NATO ally of Poland, expressed disappointment at Duda's decision.
"(This bill) ... protects Polish interests ... our dignity, the historical truth... so that we are not slandered as a state and as a nation," said Duda, an ally of the ruling Law and Justice party (PiS) which introduced the legislation.
But it also "takes into account the sensitivity of those for whom the issue of historical truth, the memory of the Holocaust is incredibly important", Duda added.
The Polish law would impose prison sentences of up to three years for using the phrase "Polish death camps" and for suggesting "publicly and against the facts" that the Polish nation or state was complicit in Nazi Germany's crimes.
PiS, a socially conservative, nationalist party that has clashed with the European Union and human rights groups on a range of issues since taking power in late 2015, says the new law is needed to ensure that Poles are recognised as victims, not perpetrators, of Nazi aggression in World War Two.
Israel says the law will curb free speech, criminalise basic historical facts and stop any discussion of the role some Poles played in Nazi crimes. Activists say the passage of the bill has encouraged a rise in anti-Semitism.
More than three million of the 3.2 million Jews who lived in pre-war Poland were murdered by the Nazis, accounting for about half of all Jews killed in the Holocaust.
Jews from across the continent were sent to be killed at death camps built and operated by Germans in occupied Poland - home to Europe's biggest Jewish community at the time - including Auschwitz, Treblinka, Belzec and Sobibor.
"JOINT RESPONSIBILITY"
Duda said he would also ask the Constitutional Tribunal for a number of clarifications about the bill. The legislation provides exemptions for academic research and art.
Duda's top foreign policy adviser Krzysztof Szczerski told public television TVP that the law should be sent to the Constitutional Tribunal within a week.
Criticising Duda's move, US Secretary of State Rex Tillerson said in a statement: "Enactment of this law adversely affects freedom of speech and academic inquiry."
Israel said it still hoped Poland would make amendments.
"We hope that within the allotted time, until the court's deliberations are concluded, we will manage to agree on changes and corrections. Israel and Poland hold a joint responsibility to research and preserve the history of the Holocaust," the Israeli government said in a statement on Twitter.
Israel's education minister said on Monday he was "honoured" Poland had cancelled his visit to Warsaw this week because he refused to retract his condemnation of the bill.
"The blood of Polish Jews cries from the ground, and no law will silence it," Bennett later said in a statement.
According to figures from the US Holocaust Memorial Museum, the Nazis, who invaded Poland in 1939, also killed at least 1.9 million non-Jewish Polish civilians.
The legislation, which comes at a time of electoral gains for anti-immigrant parties like PiS across Europe, has reopened a painful debate in Poland over the Holocaust.S
Thousands of Poles risked their lives to protect Jewish neighbours during the war. But research published since the fall of communism in 1989 showed that thousands also killed Jews or denounced those who hid them to the Nazi occupiers, challenging the national narrative that Poland was solely a victim.
The bill will also make it illegal to deny the murder of about 100,000 Poles by units of the Ukrainian Insurgent Army (UPA) during World War Two, a move likely to increase tensions with neighbouring Ukraine.