UPDATE 2-McCain concedes election, promises to help Obama

(Adds comments from McCain's speech)

By Jeff Mason

PHOENIX Nov 4 (Reuters) - Republican John McCain congratulated Democrat Barack Obama for winning the U.S. presidency on Tuesday, saying "the American people have spoken" and promising to help his former rival address the country's many challenges.

McCain addressed his supporters in an emotional speech at a Phoenix hotel after telephoning Obama to concede the election. Obama later said McCain's call had been "extraordinarily gracious."

"We have come to the end of a long journey. The American people have spoken, and they have spoken clearly," McCain said.

"Senator Obama has achieved a great thing for himself and for his country. I applaud him for it."

The 72-year-old Arizona senator urged all Americans -- including his supporters -- to rally behind Obama, saying he planned to help the new president-elect tackle the myriad issues the country faced.

"It's natural, tonight, to feel some disappointment. But tomorrow, we must move beyond it and work together to get our country moving again," McCain told his supporters, shushing them occasionally with "please, please" when they booed his mentions of Obama.

McCain and Obama clashed over the Iraq war, taxes, trade, and energy policy during a heated, five-month general election, but the Arizona senator pledged his support as the next president navigates a major financial crisis and two wars abroad.

"Senator Obama and I have had and argued our differences, and he has prevailed," McCain said, adding many of those differences remained. "These are difficult times for our country, and I pledge to him tonight to do all in my power to help him lead us through the many challenges we face."

McCain was joined by his running mate, Alaska Gov. Sarah Palin, whom he praised as a vital new voice in their party.

"We can all look forward with great interest to her future service to Alaska, the Republican Party and our country."

After a campaign that grew negative at times, most recently with Republican attacks on Obama's ties to a 1960s radical, McCain emphasized common ground between the two men.

"Whatever our differences, we are fellow Americans and please believe me when I say no association has meant more to me than that."

McCain expressed sympathy the recent death of Obama's grandmother, saying he was sorry she had not lived to see her grandson's victory.

He also acknowledged the historic nature of Obama's win.

"This is an historic election, and I recognize the special significance it has for African-Americans and for the special pride that must be theirs tonight," he said.

McCain thanked his campaign staff and his family for their support in his nearly two-year White House quest.

"Campaigns are often harder on a candidate's family than on the candidate, and that's been true in this campaign," he said. "All I can offer in compensation is my love and gratitude and the promise of more peaceful years ahead."

(Additional reporting by Steve Holland, editing by Jackie Frank)

(For full campaign coverage double click on [US/VOTE]) (For more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at http:blogs.reuters.com/trail08/)