In a letter to shareholders, Amazon CEO Jeff Bezos challenged other large retailers to raise their minimum wage to compete with Amazon.

"Today I challenge our top retail competitors (you know who you are!) to match our employee benefits and our $15 minimum wage," he wrote, prompting retaliation from Walmart.

Dan Bartlett, Walmart's vice president of corporate affairs, responded: "Hey retail competitors out there (you know who you are) how about paying your taxes?"

The gibe was a reference to Amazon's tax-efficient structure, which saw it pay $0 in federal income taxes in 2017 and 2018.

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A top Walmart executive has struck out at Amazon over its tax contributions after Jeff Bezos called out large retailers that pay their workers a lower minimum wage than Amazon's.

On Thursday, Walmart's executive vice president of corporate affairs, Dan Bartlett, tagged Bezos in a tweet that said, "Hey retail competitors out there (you know who you are 😉) how about paying your taxes?"

Bartlett was responding to Bezos' challenge to retailers on Thursday to boost their minimum wage and keep up with Amazon, which raised its minimum wage to $15 in October.

"Today I challenge our top retail competitors (you know who you are!) to match our employee benefits and our $15 minimum wage," Bezos wrote in his latest annual letter to shareholders, published Thursday.

"Do it! Better yet, go to $16 and throw the gauntlet back at us. It's a kind of competition that will benefit everyone."

Dan Bartlett, when he worked as counselor to the president in the administration of George W. Bush. AP Charles Dharapak

In 2018, Amazon paid $0 in federal income taxes for the second year in a row, despite recording a profit of $11.2 billion.

Critics say the company exploits legal loopholes to keep this figure low. Amazon says it pays all the tax required of it and points to other types of taxes that cost it billions of dollars a year.

Read more: Amazon warehouse employees speak out about the 'brutal' reality of working during the holidays, when 60-hour weeks are mandatory and ambulance calls are common

In a separate tweet on Thursday, Barlett defended Walmart's wage policy.

"FWIW, the vast majority of our warehouse associates have been making more than $15 for a long time," he said. "And they still get quarterly performance bonuses."

Read more: Jeff Bezos called for Amazon's competitors to raise their minimum wage. Here's how retail rivals like Walmart, Target, and Costco stack up on worker pay.

Walmart’s minimum wage officially became $11 an hour in January 2018.

Walmart's logo outside one of its stores in Chicago. Reuters

In a recent report on Amazon's tax affairs, the Institute on Taxation and Economic Policy said Amazon used "tax loopholes that allow profitable companies to routinely avoid paying federal and state income taxes."

It said Amazon was able to pay so little tax because its finances were structured in a way that avoided liability.

The institute highlighted Amazon's efforts to maximize tax credits and tax breaks for executive stock options as two examples of this.

"Amazon pays all the taxes we are required to pay in the US and every country where we operate, including paying $2.6 billion in corporate tax and reporting $3.4 billion in tax expense over the last three years," Amazon said in a statement issued Thursday.

"Corporate tax is based on profits, not revenues, and our profits remain modest given retail is a highly competitive, low-margin business and our continued heavy investment."

The company also pointed to the large number of jobs it had created.