WASHINGTON ― Some of America's top oil executives told President Donald Trump their companies aren't ready to invest in oil operations in Venezuela unless major changes are made to ensure the viability of the ventures.

The oil industry pointed to challenges with Trump's Venezuela oil plan as the president met with executives from 17 oil companies on Jan. 9, nearly one week after the United States military captured the country's president, Nicolás Maduro.

"We first got into Venezuela in the 1940s. We've had our assets seized twice," ExxonMobil CEO Darren Woods said. "So you can imagine, to re-enter a third time would require some pretty significant changes from what we've seen historically here and what is currently the state."

More: Trump meets with oil execs after Venezuela attack. Here's why.

Trump has said the United States will take control of between 30 billion and 50 billion barrels of Venezuela oil and is working to convince American oil companies to spend billions to upgrade aging oil infrastructure to increase the country's energy output. He has said the companies will more than earn their money back through profits, with oil sold to both Americans and Venezuelans.