Treasury Secretary Jack Lew will represent the United States at the 70th anniversary ceremony for the liberation of the Auschwitz concentration camp on Tuesday—rather than President Barack Obama or Vice President Joe Biden—while other countries are slated to send their heads of state.

Tuesday’s ceremony will likely be the last major anniversary where a significant number of survivors of the Nazi camp are present. About 300 are expected to attend, and most of them are in their 90s or older than 100. Nazi authorities killed 1.1 million people at the camp, mostly Jews, which was liberated by the Soviet army in January 1945.

The New York Times reported on the foreign dignitaries that would be present:

A preliminary list of those attending includes President François Hollande of France, President Joachim Gauck of Germany and President Heinz Fischer of Austria, as well as King Philippe of Belgium, King Willem-Alexander of the Netherlands and Crown Prince Frederik of Denmark. The United States delegation will be led by Treasury Secretary Jacob J. Lew. President Vladimir V. Putin of Russia said he would not attend because his schedule was too crowded and because he had not received an invitation. Museum officials said no head of state had received one. Mr. Putin had attended the 60th anniversary ceremony in 2005 — it was Soviet troops, after all, who liberated the camp in 1945 — but relations between Russia and Poland have soured over the conflict in Ukraine.

British Prime Minister David Cameron visited the camp last month and toured it with the state museum director.

Bernadette Meehan, National Security Council spokeswoman, said in an email that, "President Obama will be in India, on a long-scheduled trip."

The Obama administration faced a barrage of criticism earlier this month when it declined to send Obama or Secretary of State John Kerry to a march in Paris expressing solidarity with the victims of the Charlie Hebdo terrorist attack. The heads of Great Britain, Germany, and Israel all attended.