Venezuela's military has taken control of five ports in an effort to guarantee supplies of food and medicine.
In a decree, President Nicolas Maduro has ordered the army to monitor food processing plants, and co-ordinate the production and distribution of items.
Venezuela is going through a deep economic crisis despite having the world's largest oil reserves.
Basic products are increasingly hard to find and many say they struggle to feed their families.
The Venezuelan Bishops Conference said the rise of the military is a "threat to tranquillity and peace".
Mr Maduro says the measure is to fight the "economic war" he claims is being waged against his government by political foes and businessmen, with US backing.
But the opposition says the government has mismanaged the economy, and has called for a referendum to oust the president.
What is behind the shortages?
- Venezuela grows and produces very little except oil and has historically relied on imports to feed its people
- Oil prices have plummeted leaving the government with a shortfall of income
- A lack of dollars means it is struggling to import all the goods its people need and want
- The socialist government introduced price controls on some basic goods in 2003 to make them affordable to the poor
- But up to 40% of subsidised goods were smuggled across to Colombia to be sold at a profit
Mr Maduro announced on state television that the ports of Guanta, La Guaira, Puerto Cabello, Maracaibo and Guamache would be controlled by the army.
He created a government initiative called Great Mission of Sovereign Supplying, which will be headed by the country's Defence Minister, General Vladimir Padrino.
Among other things, it can establish how purchases and distribution of food, medicine and household goods are made.
Meanwhile, Mr Maduro accused Citibank of mounting a "financial blockade" on the country, after the US bank decided to close the government's international payments account with it.
Citibank said the decision followed a "periodic risk management review", but did not explain further. It would be implemented within 30 days, it added.
Due to strict currency controls in place since 2003, the Venezuelan government relies on Citibank for foreign currency transactions.