Vice-President Joe Biden also called on Kiev to tackle the “cancer of corruption”.
The US president will announce restrictions to US surveillance practices.
Joe Biden had intended to call Senator Marty Walsh, who had just been elected mayor of Boston.
The name of the most paid employee in the White House has been revealed.
The service at the Massachusetts Institute of Technology will honours Sean Collier, 26.
The US Senate voted to avoid imminent tax hikes and spending cuts in a bipartisan deal.