The U.S. is preparing measures ranging from criminal charges to sanctions against people it believes to be involved in Venezuela’s military-run emergency food program, according to U.S. officials, part of an effort to target what they describe as a large-scale money-laundering operation run by the government.

The measures are expected to be rolled out in the coming weeks and months as part of a bid to increase pressure on the Caracas regime. The U.S. and many other countries have recognized the political opposition as Venezuela’s legitimate government, but President Nicolás Maduro—supported by Cuba and Russia—has held on to power, squelching a recent U.S.-backed push to force him out.

The U.S. government is preparing to allege in criminal charges and sanctions that Venezuelan officials and private contractors, including a Colombian businessman, have laundered billions of dollars in state funds meant for the food program and other state operations, the officials and other people familiar with the matter said.

Through the alleged money-laundering networks, some of these people amassed large sums in overseas accounts, as well as U.S. real estate, yachts and airplanes, according to a senior U.S. Treasury official. Venezuela’s economy has collapsed in recent years, causing widespread malnutrition and hyperinflation.

Caracas said the accusations are part of a U.S. smear campaign. “The U.S. thinks it will bring us to our knees with attacks, threats and coups,” Mr. Maduro said in an April speech. “But we will never surrender.” His office has said the investigations of the emergency food program are an attempt to sabotage the country’s ability to import food. Venezuela’s Information Ministry didn’t respond to requests to comment for this article.