(Reuters) - Potential U.S. sanctions on Venezuela’s crude oil exports would cut off the nation from Gulf Coast refiners that are among its biggest customers, likely forcing it to send more crude to China, India or other Asian countries, traders said on Wednesday.

FILE PHOTO: An oil tanker is seen at Jose refinery cargo terminal in Venezuela in this undated file photo. REUTERS/Jorge Silva/File Photo

U.S. refineries that depend on Venezuela’s heavy crude would have even more trouble securing supplies as Canadian and Mexican crudes are often not as discounted and are limited in availability.

The United States is considering moves to cripple Venezuela’s oil shipments, which account for nearly all of the country’s exports, in response to the reelection of President Nicolas Maduro that was widely viewed as a sham.

Washington has recognized opposition leader Juan Guaido as Venezuela’s president as protests against Maduro erupted across the country. It is also considering sanctions on oil deliveries, a move it has until now resisted, energy company sources told Reuters on Wednesday.

Venezuela, on average, exported about 500,000 barrels of crude a day to the United States in 2018, according to U.S. Energy Department data. Those shipments fell in November to an estimated 358,000 barrels per day, however, according to a report by Caracas-based consultancy Gas Energy Latin America seen by Reuters.

The U.S. share of its exports has declined in recent years with more shipments going to Russia and China. [GRAPHIC: Venezuelan crude exports to the United States: tmsnrt.rs/2S4YIXB]

Those deliveries are being made largely through oil-for-debt repayment structures as output from state-run oil company Petróleos de Venezuela, S.A., known as PDVSA, has slumped to near 70-year lows in a nationwide economic crisis. Venezuela’s output has been cut in half since 2016 to less than 1.2 million bpd, according to figures from OPEC secondary sources.

Shipments to the United States account for about 75 percent of the cash Venezuela gets for crude shipments, according to a Barclays research note published last week.

In the wake of sanctions, the country could seek additional deals with Turkey, India or other Asian nations, one trader of Venezuelan crude said. Gas Energy’s report said India was the second-largest importer of Venezuelan crude in November.

“It will be costly for Venezuela but eventually they’ll be able to sell that oil to Asia at a discount. There will be a period in the middle in which they have difficulty selling those barrels,” said Francisco Monaldi, fellow in Latin American Energy Policy at the Baker Institute for Public Policy at Rice University in Houston.

[GRAPHIC: Top U.S. importers of Venezuelan crude: tmsnrt.rs/2RYGk2E]

Though the United States produces nearly 12 million barrels of oil a day, complex Gulf Coast refineries need heavier crude grades to produce diesel and other high-margin products, and cannot simply sub in light crude.

Prices of heavier U.S. grades like Mars Sour, an offshore medium U.S. crude, and Heavy Louisiana Sweet crude have risen as buyers scramble for supply. Mars traded at a $6.90 premium to U.S. crude on Wednesday, a five-year high, according to Refinitiv Eikon data, as bidders came into the market to secure supplies through the second quarter, traders said.

“It would make a tight market even tighter. If it happens, it would be an unambiguous headwind for refiners already struggling to find supplies,” said Bob McNally, president of Rapidan Energy Group, an energy consultancy in Bethesda, Maryland.

[GRAPHIC: Venezuelan crude exports to U.S. refiners: tmsnrt.rs/2S42EI5.]

Traders said the United States may need to sell oil from the U.S. Strategic Petroleum Reserve to cover supply shortfalls as additional shipments are secured via Canada or Mexico.

Sanctions could also include U.S. exports of petroleum products to Venezuela, used for blending with Venezuelan heavy crude.