Image copyright Getty Images Image caption Paul Ryan said being elected House speaker is a "great honour"

Republican Paul Ryan from Wisconsin has been elected as the new Speaker of the US House of Representatives.

Hesitant to run at first, he eventually gained support of the majority of Republicans in Congress to succeed John Boehner of Ohio for the job.

The 45-year-old Mr Ryan was Republican presidential candidate Mitt Romney's running mate in the 2012 election.

He has helped determine budget and tax policy in Congress and said he only wanted the job to unify Republicans.

In his new position, he will be second in line to the presidency only behind the vice-president.

Among other responsibilities, the speaker acts as presiding officer over the lower chamber of Congress for administrative and business matters.

Analysis - Anthony Zurcher, BBC News, Washington

Paul Ryan gives the Republican-controlled Congress the kind of compelling, charismatic leader it has sorely lacked since Newt Gingrich first rocketed to prominence more than two decades ago.

The irony, however, is that Ryan's rise as the face of his party has occurred only a handful of months before he will be wholly eclipsed by whoever the Republicans choose as their standard-bearer in the 2016 presidential election.

While he may promise to lead a Congress that respects differences of opinion and works together to solve the nation's problems, the reality is that the chance to set the tone of the political debate has even now all but moved away from Washington, DC.

It instead rests on the campaign hustings, in places like New Hampshire and Iowa, where numerous candidates have made their names railing against their party's leadership. A change of course at this point is unlikely in the extreme.

If an insurgent presidential hopeful like Ted Cruz, Donald Trump or Ben Carson becomes their party's nominee, any hopes Mr Ryan may have of cooling the fever in Congress will surely be dashed.

Who is Paul Ryan?

Mr Ryan received roaring applause in the House chambers upon his election.

He thanked Mr Boehner for his work over the years and called him a "man of character".

Image copyright Reuters Image caption Paul Ryan (centre) is succeeding John Boehner (back)

Democrats and Republicans must pray for one another, he said.

He called for a "return to order" in the House, speaking frankly about the discord that has been plaguing House Republicans.

"We're not solving problems, we're adding to them," he said. "We're not settling scores, we're wiping the slate clean."

"It's not a matter of process, it's a matter of principle. Only a fully functioning House can truly represent the people."