March 29, 2010
President Obama called Russian President Medvedev today to personally convey the condolences of the American people on the loss of life and injuries resulting from the outrageous terrorist act in Moscow. President Obama said that the United States was ready to cooperate with Russia to help bring to justice those who undertook this attack.
Barack Obama, Readout of the President's Call with Russian President Medvedev Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/290459