U.S. President Barack Obama is urging his supporters to fight for him in the 2012 presidential campaign, as they did to get him elected in 2008.

President Obama spoke from Washington in a video teleconference to attendees at the Iowa caucuses. Iowa is holding Republican and Democratic Party caucuses Tuesday, the first nominating contests in the 2012 presidential election.

He highlighted major accomplishments of his administration, including passage of reform on Wall Street and health care, ending the war in Iraq, and reversing the ban on openly homosexual people serving in the military.

The president, who ran unopposed in the Democratic Party caucuses, told supporters that his administration's progress can only be maintained if they display the same energy that propelled him to the White House in 2008.

“You guys inspire me every single day. And I want us to remind ourselves, and to remind each other, that as much work as there may be out there before us, there is nothing we can't accomplish when determined citizens come together and decide they want to make a difference.”

He said more work remains and that the problems of the last three years did not happen “overnight” and will not be fixed “overnight”.

Republicans hoping to win the White House have been vocal critics of the president, saying they hope to repeal health care and change the direction of the country.