The chief executive of U.S. automaker Chrysler says his company is not shifting production of Jeep vehicles to China. His comments follow a series of statements by Republican presidential candidate Mitt Romney's campaign that appear to suggest otherwise.

Chrysler CEO Sergio Marchionne said in an email to employees Tuesday that Jeep assembly lines will remain in operation in the United States, saying “it is inaccurate to suggest anything different.”

The strongly worded statement, which did not mention Mr. Romney directly, came just a week before the U.S. presidential election, which is focused heavily on the politically important “swing state” of Ohio, where many U.S. automakers have factories.

The Romney campaign has aired recent television and radio ads in Ohio suggesting that Jeep, which received federal bailout money, is shifting American jobs to China. Mr. Romney told an Ohio crowd last week that he heard reports that Jeep “was thinking of moving all production to China.”

Marchionne acknowledged Tuesday that Jeep's parent company, Chrysler, does plan to expand production in China, the world's largest auto market. But he said the plan does not involve cutting its American work force, and insisted that his company is instead adding new U.S. jobs.

The Romney campaign did not comment on the email Tuesday, but a campaign advisor told the Huffington Post that if jobs are added in China, that amounts to jobs not added in the United States.

Mr. Romney's statement last week appears to be based on a Bloomberg article published last Monday that said Chrysler “plans to return Jeep output to China and may eventually make all of its models in that country.” Bloomberg later added a line to the story saying the company planned to add production sites rather than shift production.

The Romney campaign later released television and radio ads that simply state that Jeep soon intends to build Jeeps in China, and promising that Mitt Romney “will fight for every American job.” But several fact-checking organizations have criticized the ads for not mentioning that no American jobs will be lost as a result of the expanded production.

The Republican presidential candidate has taken a tough stance on China, saying President Barack Obama has not done enough to stand up to its alleged trade violations, which he says are hampering the U.S. economic recovery.