U.S. President Barack Obama may attend the funeral of Polish president Lech Kaczynski, who died Saturday morning in an aircrash near Smolensk, Russia, Polish Foreign Minister Radoslaw Sikorski said Monday on radio.

Sikorski said Russian President Dmitry Medvedev would also be present at the funeral.

Asked about Obama's attendance, Sikorski said he "didn't know that for sure" but added that the U.S. president had sent a letter to Poland's ambassador in Washington and his presence in Warsaw "was not to be excluded."

Sikorski said Poland was receiving "enormous amounts of condolences" from all over the world.

On Saturday morning, a Polish plane carrying President Kaczynski, his wife Maria and over 80 leading Polish political personages for anniversary celebrations of the 1940 Katyn Massacre crashed while approaching the airport in Smolensk.

No one survived the accident. Killed besides the presidential pair were Poland's entire military command, several vice ministers and numerous MPs and senators.