US President Barack Obama's re-election campaign says if Mitt Romney releases five years of his tax returns, it will not press the Republican presidential challenger to release more - a proposal quickly rejected by Romney's campaign.
Democrats have criticized Romney for not providing more than two years of tax information and questioned whether the millionaire former private equity executive has something to hide about his wealth.
Romney said on Thursday he had paid at least a 13 percent tax rate for the last 10 years, but did not release tax documents. The former Massachusetts governor called Democrats' focus on his taxes a distraction from the issues of jobs and the economy.
"Governor Romney apparently fears that the more he offers, the more our campaign will demand that he provide," Obama campaign manager Jim Messina said in a letter to Romney campaign manager Matt Rhoades.
"So I am prepared to provide assurances on just that point," Messina wrote, saying if Romney releases taxes from 2007 through 2012, "I commit in turn that we will not criticize him for not releasing more - neither in ads nor in other public communications or commentary for the rest of the campaign."
Rhoades shot back: "It is clear that President Obama wants nothing more than to talk about Governor Romney's tax returns instead of the issues that matter to voters, like putting Americans back to work, fixing the economy and reining in spending."
Last month, Senate Majority Leader Harry Reid, a Democrat, accused Romney of not paying taxes for 10 years, which Romney strongly denied.
Polls indicate that Democrats' focus on Romney's finances - depicting him as out of touch with ordinary Americans - is working among independent voters in swing states.
Romney is one of the richest men ever to run for U.S. president, with an estimated net worth of up to $250 million.
In January he released information showing he had paid an effective tax rate of 13.9 percent in 2010, mostly from capital gains on investments. The top tax rate for wages is 35 percent, while capital gains are taxed at a lower rate.
In his letter, Messina said other presidential candidates have provided more than the two years of returns offered by Romney, "including the Governor's father who provided 12 years of returns." Romney's father George, a former Michigan governor, ran unsuccessfully for president in 1968.
Messina said the additional tax returns would help answer questions "such as the range in the effective rates paid, the foreign accounts maintained, the foreign investments made, and the types of tax shelters used."
Rhoades responded that if Romney's tax returns "are the core message of your campaign, there will be ample time for President Obama to discuss them over the next 81 days," the time remaining until the Nov. 6 presidential and congressional elections.
Rhoades signed off his note, "See you in Denver," the site of the first debate between the candidates, on Oct. 3.
