Venezuela's self-proclaimed president Guiado speaks with Trump

US President Donald Trump has stressed to Venezuelan opposition leader Juan Guaido his "strong support" for the nation's fight to regain its democracy, the White House says.

Trump and Guaido spoke by telephone on Wednesday.

The White House said Guaido thanked Trump for committing the US to freedom and prosperity in Venezuela and the region.

The leaders also agreed to regular communication in support of Venezuela's path back to stability and to rebuild strained relations between both countries.

"I appreciate the phone call from the president of the United States, Donald Trump, who reiterated his complete support for our democratic work, commitment to humanitarian aid and his administration's recognition for our (interim) presidency," Guaido wrote on Twitter.

Large protests are planned across Venezuela on Wednesday to increase pressure on President Nicolas Maduro to step down.

Guaido declared himself Venezuela's rightful leader last week and said the nation "is set on change".