WASHINGTON — Facing down blistering criticism on Capitol Hill that Apple sidestepped billions of dollars in taxes, the company’s chief executive, Tim Cook, carefully defended Apple’s record Tuesday, rejecting any suggestion of misconduct but avoiding clashes with skeptical legislators.

“It’s important to tell our story, and I’d like people to hear directly from me,” Cook told a Senate panel during questioning by Sen. John McCain, R-Ariz. Apple, he said, pays “all the taxes we owe — every single dollar.”

Rather than taking unfair advantage of what congressional investigators say are a host of tax code loopholes, Cook said his company was actually a victim of an outdated tax system.

“Unfortunately, the tax code has not kept up with the digital age,” Cook said. “The tax system handicaps American corporations in relation to our foreign competitors who don’t have such constraints on the free movement of capital.”

On Monday, congressional investigators unveiled a detailed report showing how Apple subsidiaries based in Ireland but spanning other regions had helped the company pay as little as one-twentieth of 1 percent in taxes on billions of dollars in income.

Cook sought to draw a sharp distinction between sales in the U.S. and those abroad, arguing the company had complied with local laws everywhere.

“The way I look at this is that Apple pays 30.5 percent of its profits in taxes in the United States,” he said. “We do have a low tax rate outside the U.S., but this is for products we sell outside the U.S.”

Before Cook and two other top Apple executives testified, however, other witnesses suggested Apple had pushed to take advantage of the tax code.

J. Richard Harvey Jr., a professor at Villanova Law School, estimated that Apple’s legal maneuvering had saved the company $7.7 billion in potential American taxes in 2011.