WASHINGTON (Reuters) - The Trump administration on Friday expanded the scope of its Venezuela sanctions to the defense and security services sectors to try to crank up economic pressure on Venezuelan President Nicolas Maduro.

The White House is keen to show that momentum in its four-month-old campaign against Maduro has not waned, particularly after a failed uprising last week led by opposition leader Juan Guaido, who is backed by the United States and most Western nations.

Guaido - who Maduro has called a puppet of Washington - invoked Venezuela’s constitution in January to assume an interim presidency, arguing Maduro’s 2018 re-election was illegitimate.

Despite significant U.S. oil sanctions on the OPEC member nation, Maduro has held on to power, backed by Cuba, Russia and China, and retains the support of the country’s military and other institutions.

U.S. President Donald Trump spoke with Russian President Vladimir Putin a week ago, a conversation that revealed Moscow to be relatively disinterested in the fate of Maduro, according to a senior U.S. administration official who spoke on condition of anonymity.

“I think it was clear from the call, at least to us, that Putin doesn’t care about Venezuela,” the official told a small group of reporters. “It’s a chit for bigger geopolitical issues,” the official said, noting that Putin described Maduro as economically incompetent.

Under Maduro’s leadership, Venezuela’s economy has ground to a halt, causing shortages of food, power, water and medicine, and prompting an exodus of millions from the oil-rich country.

Guaido’s April 30 uprising failed to result in widespread change, but left Maduro “cornered” and desperate, the official said.

One former general turned against Maduro, and this week he was taken off the U.S. sanctions blacklist. The general, Manuel Cristopher, has been in touch with U.S. officials, and contacts from other military figures have also surged, the official said.

The Treasury Department said on Friday that U.S. and foreign companies working with Venezuela’s defense and security services sectors can now be sanctioned, adding to penalties for companies working in the oil and banking sectors.

The move puts on notice foreign suppliers of military spare parts or telecommunications equipment and services, the U.S. official said.

The Trump administration also blacklisted two new shipping companies and two oil tanker ships for shipping oil from Venezuela to Cuba.

The U.S. Treasury identified the firms as Monsoon Navigation Corp, based in the Marshall Islands, and Liberia-based Serenity Navigation Ltd.

Monsoon’s tanker Ocean Elegance and Serenity Maritime’s Leon Dias delivered crude oil from Venezuela to Cuba from late 2018 through March 2019, the Treasury Department said. Both tankers have Panama flags.

The sanctions block the firms and ships from dealings with U.S. persons and companies, and freeze any assets the firms may own or control in the United States.