Poland warned on Monday it may pull out of a summit of central European nations in Jerusalem this week, after comments by Israel's new foreign minister accusing Poles of anti-Semitism.
The foreign ministry also summoned Israeli ambassador Anna Azari over the remarks by Israel Katz on Sunday, the PAP news agency reported, the second time Warsaw has taken such action in a matter of days.
Prime Minister Mateusz Morawiecki had backed out of the summit on Sunday following uproar over reported comments by his Israeli counterpart Benjamin Netanyahu about Poles and the Holocaust.
Foreign Minister Jacek Czaputowicz was due to replace Morawiecki, but the prime minister said on Monday that Warsaw's participation was now in question following the Katz comments.
Katz told Israel's i24 television that "there were many Poles who collaborated with the Nazis, and like Yitzhak Shamir, whose father was murdered, said: Poles suckle anti-Semitism with their mothers' milk."
"We're waiting for a firm reaction to the unpardonable and simply racist words of Israel's new foreign minister, which is something that can't be left without reaction," Morawiecki told Polish media.
"If there is no such reaction on the other side, we'll wish them the best possible meeting, but minister Jacek Czaputowicz will also not attend," Morawiecki said.
The matter would be decided "in two-three hours", he added.
The Visegrad Group, also known as the V4, comprises the Czech Republic, Hungary, Poland and Slovakia. It is due to hold its first summit in Jerusalem Monday and Tuesday for talks with Israeli officials.
The initial row broke out last week when Netanyahu -- who was quoted in Haaretz newspaper as saying that "the Poles collaborated with the Nazis" -- was condemned in Poland for appearing to accuse all Polish people of cooperating with Germany during World War II.
Warsaw has long been at pains to state that Poland, which was occupied by Nazi Germany, could not have and did not collaborate in the Holocaust although individual Poles gave up Jews to the Nazis.
The Israeli prime minister's office said on Friday that Netanyahu had not implicated all Poles in the Holocaust.
It insisted that Netanyahu was "misquoted" in Haaretz and other publications that reported different versions of the quote.
The clarification came hours after the Polish foreign ministry had summoned Azari over the remarks.
Netanyahu was in Warsaw last week for a two-day summit on the Middle East, co-hosted by Poland and the United States, which focused on isolating Iran while building Arab-Israeli ties.
The fresh controversy in Polish-Israeli ties comes after a row last year over a Polish law that made it illegal to accuse the Polish nation or state of complicity in Nazi German crimes.
After protests from Israel and the United States, Poland amended the law to remove the possibility of fines or a prison sentence.
Poland was occupied by Nazi Germany during World War II and lost six million citizens including three million Jews.