Michael Bloomberg seen furiously nodding in approval.

WASHINGTON (AP) — Food companies and restaurants could soon face government pressure to make their foods less salty — a long-awaited federal effort to try to prevent thousands of deaths each year from heart disease and stroke.

The Food and Drug Administration is preparing voluntary guidelines asking the food industry to lower sodium levels, FDA Commissioner Margaret Hamburg told The Associated Press. Hamburg said in a recent interview that the sodium is “of huge interest and concern” to the agency.

“We believe we can make a big impact working with the industry to bring sodium levels down, because the current level of consumption really is higher than it should be for health,” Hamburg said.

It’s still unclear when FDA will release the guidelines, despite its 2013 goal to have them completed this year.

Hamburg said she hoped the agency would be able to publicly discuss the issue “relatively soon.” On Tuesday, FDA spokeswoman Erica Jefferson said there is no set timeline for their release.

The food industry has already made some reductions, and has prepared for government action since a 2010 Institute of Medicine report said companies had not made enough progress on making foods less salty. The IOM advised the government to establish maximum sodium levels for different foods, though the FDA said then — and maintains now — that it favors a voluntary route.

Health groups would prefer mandatory standards, but say voluntary guidelines are a good first step.

Still, Michael Jacobson of the Center for Science in the Public Interest says he is concerned companies may hesitate, worried that their competitors won’t lower sodium in their products.

If that happens, “then FDA should start a process of mandatory limits,” Jacobson says.

That’s what companies are worried about. Though the limits would be voluntary, the FDA is at heart a regulatory agency, and the guidelines would be interpreted as a stern warning.