The phrasing is considered hugely offensive in Poland, where Nazi Germany murdered Poles, Jews and others in death camps it built during World War II on Polish and German territory. Poles have responded with outrage, saying Obama should have called it a "German death camp in Nazi-occupied Poland" to distinguish the perpetrators from the location.
President Bronislaw Komorowski said he has written to Obama and hopes the letter will lead to a "joint correcting of the unfortunate mistake" that could prevent the use of such phrases in the future.
"In my opinion, the words of the U.S. president - unjust and painful to us all - about a Polish death camp, do not reflect either the views or the intentions of our American friend," Komorowski told a news conference.
White House spokesman Jay Carney on Wednesday reiterated the administration's earlier assertion that Obama simply misspoke when he referred to "Polish death camps."
"This was a simple mistake and we regret it," he said. "It was Nazi death camps that the president was referring to."
Carney said Obama had not spoken to Prime Minister Donald Tusk.
Earlier Wednesday, Tusk said he was accepting a White House explanation that Obama "misspoke" but was still waiting for a "stronger, more pointed reaction" that could eliminate the phrasing "once and for all." Tusk said it was a "matter of the U.S.'s reputation." He hinted it should include facts about Nazi Germany's brutal occupation of Poland, during which 6 million Polish citizens were killed, half of them Jews.
Stressing that the entire Polish nation felt affected by Obama's words, Tusk said: "We always react in the same way when ignorance, lack of knowledge, bad intentions lead to such a distortion of history, so painful for us here in Poland, in a country which suffered like no other in Europe during World War II."
"When someone says `Polish death camps,' it is as if there were no Nazis, no German responsibility, as if there were no Hitler - that is why our Polish sensitivity in these situations is so much more than just simply a feeling of national pride," Tusk said.
Former President and Solidarity founder Lech Walesa said the phrase confused henchmen with their victims but that Obama's mistake might prevent similar statements by others.
Foreign Minister Radek Sikorski thanked Obama for honoring Poland's "national hero" and expressed hope that the "unfortunate words" will serve as foundations for jointly educating the world about Poland's role in World War II.
The White House said the president misspoke Tuesday in bestowing the Medal of Freedom posthumously on Jan Kozielewski, alias Karski, a Polish emissary who in 1943 alerted Allied leaders in London and Washington to mass killings of Jews in Europe and in Nazi-occupied Poland. In order to gather first-hand evidence he risked his life and was secretly smuggled into the Warsaw Ghetto and a death camp. His account was met with disbelief and brought no reaction.
Anxious to quell the current controversy, the White House also noted that the president visited the Warsaw Ghetto Memorial while in Poland last year and that he has repeatedly discussed the bravery of Poles during World War II.
The Polish Embassy in Washington, on its website, has a "how-to guide" on concentration camps that states that references to Polish death camps are "factually incorrect slurs" that should be corrected.
Warsaw's Jewish community also said it found the Obama's language "deeply upsetting," even though it is clear he meant no disrespect.
"Though it should be obvious he referred to geographical location only, and no slur on Poland was intended, the phrase carries a potential (for) misinterpretation," it said, adding that it is "injurious to the very values and accomplishments" of the Polish anti-Nazi resistance.
"We expect President Barack Obama to personally rectify his choice of words," the Jewish community added.