The US is to award the British Prime Minister the Congressional Gold Medal.
Mr Tony Blair will follow Winston Churchill to become only the second Briton to receive the award.
Senator Elizabeth Dole, wife of the former presidential candidate Bob Dole, has proposed legislation to recognise Mr Blair's "outstanding and enduring contributions to maintaining security of all freedom-loving nations".
The bill has 78 supporters in the 100-seat Senate - 11 more than is required - and could be passed next week.
Previous winners also include Nelson Mandela, Mother Teresa and Pope John Paul II.
Mrs Dole, a North Carolina Republican, praised Mr Blair for sticking with his principles in the face of "shifting political winds."
"Prime Minister Blair has proven to be one of the strongest and most distinguished allies of the United States in our efforts to rid the world of terrorists," she said. "He deserves nothing less than our highest accolades."
Mr Blair's support for the Bush administration during the wars in Afghanistan and Iraq made him hugely popular in the US.
He has also been named as the first non-American to receive the Ellis Island Medal of Honour for his role in the war against terrorism.
AP