WASHINGTON (Reuters) - President Barack Obama told Americans on Sunday a substantial number of the 140,000 U.S. troops in Iraq would be home within a year, saying Iraqis were now ready to take more responsibility for their own security.

Obama, who inherited two wars in Iraq and Afghanistan, pledged during his presidential campaign to withdraw all U.S. troops from Iraq within 16 months, at a rate of one or two brigades a month.

In an interview with NBC television, Obama praised the provincial elections held in Iraq at the weekend, the most peaceful polls since U.S.-led forces invaded in 2003 to topple Saddam Hussein.

Asked in the NBC interview whether a substantial number of troops would be home in time for next year’s Super Bowl, the National Football League’s championship game being played on Sunday, Obama replied: “Yes. We are going to roll out in a very formal fashion what our intentions are in Iraq as well as Afghanistan.”

The Obama administration has launched a comprehensive review of America’s strategy in Afghanistan, where NATO-led forces are struggling to cope with spiraling violence and a resurgent Taliban militancy.

The administration is considering almost doubling the U.S. force in Afghanistan from 36,000 to more than 60,000 within 18 months.

Obama, who held talks with the Joint Chiefs of Staff at the Pentagon last week, has said he wants a responsible and phased withdrawal of U.S. troops from Iraq. The United States signed a military deal with Iraq last year that set a 2011 deadline for U.S. forces to quit the country.

“In conversations I have had with the joint chiefs, with commanders on the ground, I think we have a sense, now that the Iraqis just had a very significant election with no significant violence, we are in a position to put more responsibility on the Iraqis,” Obama said in the interview.

He also said one of the more sobering moments of his young presidency was having to sign letters to send to families of slain soldiers.

Some 644 U.S. soldiers have been killed in Afghanistan and 4,236 in Iraq.