The Democrats have included language about Jerusalem being the capital of Israel in their party platform despite initially omitting it.

Four years ago the phrase "Jerusalem is and will remain the capital of Israel" appeared in the party's manifesto. Its absence as President Obama prepares to seek re-election caused consternation among voters and political groups, with the Orthodox Union calling it "extremely disappointing".

But on Wednesday, with the Democratic National Convention underway in North Carolina, the party clarified its position and said the line would go back in.

"The platform is being amended to maintain consistency with the personal views expressed by the president and in the Democratic Party platform in 2008," said DNC chair Debbie Wasserman Schultz.

"Jerusalem is and will remain the capital of Israel. The parties have agreed that Jerusalem is a matter for final status negotiations. It should remain an undivided city accessible to people of all faiths."

The DNC also reinstated language about a government helping people live up to "their God-given potential".

"We welcome the amendment referencing Jerusalem as Israel's capital and we applaud the DNC for listening and for being responsive to the concerns raised by supporters of Israel," said Abraham Foxman, national director of the Anti-Defamation League.

"But we are still troubled that it was removed, and it should never have happened in the first place."