CHICAGO — President-elect Barack Obama took his first public steps toward building his new administration yesterday, tapping fellow Chicagoan Rep. Rahm Emanuel to be the White House chief of staff.

Obama also received his first top-secret briefing on national security, scheduled a meeting today with his economic advisers to be followed by a news conference and accepted an invitation for his wife and him to visit President Bush and Laura Bush at the White House on Monday.

The president-elect also talked by telephone with nine world leaders, who all had called to congratulate Obama for his election victory. Among the U.S. allies he spoke with the top politicians in Israel, Japan and Mexico.

The pick of Emanuel, a veteran of the Clinton White House who's now a top leader in the House of Representatives, suggested that Obama wants a tough taskmaster to run his White House as well as a steely insider who's able to help push the Obama agenda through Congress.

It also signaled a possible shift in tone from his campaign and his willingness to offend some Republicans — and Democrats, for that matter — if necessary to get what he wants.

Emanuel, 48, has represented a north Chicago district in the House since 2003. He chaired the Democrats' campaign to retake the House majority in 2006, which succeeded. He's the fourth-ranking Democrat in the House as the chair of the Democratic caucus.

"I announce this appointment first because the chief of staff is central to the ability of a president and administration to accomplish an agenda. And no one I know is better at getting things done than Rahm Emanuel," Obama said in a statement.

He said Emanuel's seven years in the Clinton White House and six years in Congress gave him invaluable experience in the way government worked, while his post-White House work as an investment banker helped give him "deep insights into the challenging economic issues that will be front and center for our administration."

Emanuel, in the statement, called himself humbled and honored, saying he decided to leave his post in Congress only because he thought he could help Obama.

He offered a rare salute to Republicans, saying they serve with "dignity, decency and a deep sense of patriotism." He added, "I will do everything in my power to help you stitch together the frayed fabric of our politics, and help summon Americans of both parties to unite in common purpose."

News of Emanuel's appointment angered some Republicans.

"This is an ironic choice for a president-elect who has promised to change Washington, make politics more civil and govern from the center," said Rep. John Boehner, R-Ohio, his party's leader in the House.

However, Sen. Lindsey Graham, R-S.C., noted that he'd worked well with Emanuel when the two were negotiating rules for this year's presidential debates, and called Emanuel a "wise choice" who'll help Obama enact his agenda.

"Rahm knows Capitol Hill and has great political skills. He can be a tough partisan but also understands the need to work together," Graham said. "He's tough but fair. Honest, direct, and candid. These qualities will serve President-elect Obama well."