Venezuelan Defense Minister Vladimir Padrino said Friday that U.S. national security adviser John Bolton has been sending him messages asking him to do the "right thing."

"Mr. Bolton, I tell you that we are doing the right thing," Padrino said in televised comments. "Doing the right thing is doing what's written in the constitution. ... Doing the right thing is respecting the will of the people."

It was not immediately evident if Padrino was referring to Bolton's recent tweets, in which he made direct mention of Padrino.

Bolton said Friday that U.S. President Donald Trump is considering imposing sanctions on companies from other countries that do business with Venezuela to cut off revenues to President Nicolas Maduro.

"We're moving exactly in that direction," Bolton told Reuters TV when asked whether Trump would consider what are known as "secondary sanctions."

"We are even now looking at a series of additional steps we could take," Bolton said in the interview.

The United States and most other Western countries have thrown their backing behind Venezuelan opposition leader Juan Guaido, who declared himself interim president in January.

Oil provides 90 percent of export revenue for OPEC member Venezuela. The United States imposed sanctions on Venezuela's state-owned oil company PDVSA in January, preventing U.S. companies from dealing with it unless revenues went to a fund available to Guaido.

The Trump administration has not yet slapped sanctions on companies from other countries that do business with PDVSA - but U.S. officials have been having "conversations" with oil trading houses and governments around the world to convince them to scale down their dealings with Maduro, Trump's Venezuela envoy Elliott Abrams said earlier Friday.

Turkey, Russia and China support Maduro, who has said Guaido is a puppet of Washington.