Updated

President Obama says the death of Libya's Muammar Qaddafi and the end of the Iraq war are powerful reminders of America's renewed leadership in the world.

At the same time, Obama said Saturday that the U.S. now must tackle its "greatest challenge as a nation" -- rebuilding a weak economy and creating jobs -- with the "same urgency and unity that our troops brought to their fight."

Obama informed the nation on Friday that the long and costly war in Iraq will be over by the end of the year and that some 40,000 U.S. servicemen and women still there "will definitely be home for the holidays."

A day earlier, he hailed the killing of Libya's longtime leader as a "momentous day" in the history of a country that Qaddafi had ruled for decades through tyranny.

Obama said in his weekly radio and Internet address that these foreign policy successes were part of a larger story.

"This week, we had two powerful reminders of how we've renewed American leadership in the world," Obama said. "After a decade of war, we're turning the page and moving forward, with strength and confidence."

He said withdrawing troops from Iraq has allowed the U.S. to focus on Afghanistan and score major victories against al-Qaida, including the killing in May of terrorist mastermind Osama bin Laden. Troops also have been coming home from Afghanistan.

Obama said ending both wars will allow the U.S. to focus on rebuilding a weak economy so it can start creating enough jobs to reduce high levels of unemployment. That could possibly aid his re-election bid, which is being jeopardized by the tough financial circumstances.

"Over the past decade, we spent a trillion dollars on war, borrowed heavily from overseas and invested too little in the greatest source of our national strength -- our own people," the president said. "Now, the nation we need to build is our own."

In the Republicans' weekly message, Sen. Richard Burr, R-N.C., bemoaned 32 consecutive months with unemployment above 8 percent.

While Obama on Saturday called anew or passage of his $447 billion jobs bill, Burr urged action on a Republican alternative.

Senate Republicans recently blocked Obama's overall bill, leaving Democrats in charge of the chamber to try to pass it piece by piece. But Republican senators also blocked action on the first component of the larger bill, a $35 billion measure to boost hiring of teachers and emergency services workers.

In turn, Democrats stalled a measure both parties support that would stop the government from withholding 3 percent of payments to government contractors.

A test vote is expected next month, after the Senate returns from vacation, on a $60 billion bill to finance construction of roads, bridges and other public works projects.

Burr said people are hurting and the economy is in "grave danger."

"It's time for Congress to focus on the American people and not how difficult change might be," he said. "It's time stop playing games and to get on with the serious business that the American people expect from us."