Democratic presidential candidate Barack Obama says President Bush has abdicated the role of leader of the free world and the 2008 election is a chance to change that.

"This President may occupy the White House, but for the last six years the position of leader of the free world has remained open. And it's time to fill that role once more," according to excerpts of a speech Obama is scheduled to deliver Monday to the Chicago Council on Global Affairs.

The Illinois senator was back in his hometown to deliver the foreign policy address that was rescheduled last week after the shootings at Virginia Tech.

Obama also says the world is disappointed in America.

"The disappointment that so many around the world feel toward America right now is only a testament to the high expectations they hold for us. We must meet those expectations again, not because being respected is an end in itself, but because the security of America and the wider world demands it," according to the speech.

Monday's speech is the third time in recent months that Obama has come home to deliver a foreign policy address.

In a March speech before the American Israel Public Affairs Committee, a bipartisan pro-Israel lobby, he blamed Bush Administration failings in Iraq for strengthening the strategic position of Iran. He called for a reduction of U.S. forces in Iraq, during a November address before the Chicago Council on Global Affairs.