The arrival of a severe thunderstorm Monday scuttled President Obama's plans to pay the nation's respects to America's war dead at the Abraham Lincoln National Cemetery in Elmwood, Ill.

After urging the thousands gathered to hear him to return to their vehicles for their safety, Obama boarded a pair of buses to greet the military families who attended the event.

Later, he met privately with families of veterans and service members at the Fisher House in Hines, Ill., a non-profit facility that provides temporary housing for families of wounded veterans undergoing rehabilitation.

Meanwhile, Vice President Joe Biden appeared at Arlington National Cemetery in Washington, D.C. where he took part in the traditional wreath-laying ceremony. There he hailed America's military men and women as "spine of this nation."

"As a nation, we pause to remember them," Biden said. "They gave their lives fulfilling their oath to this nation and to us."

The president has drawn fire from veteran's groups for breaking with the tradition of the sitting president laying a wreath at Arlington, which is regarded by many as one of the nation's most hallowed burial grounds.

Obama spoke at the Lincoln cemetery in 2005. He and his family spent the holiday weekend at their home in Chicago.