Venezuela's self-declared interim president, Juan Guaido, has announced a "gradual" strike in the public sector to put pressure on President Nicolas Maduro, even as the threat of being arrested still hangs over him.

"Public sector employees, workers, trade unions will not continue cooperating with ... a regime that jails and persecutes them," Guaido said at a meeting with unions in Caracas on Tuesday.

He said there would be a "gradual" strike involving "all the sectors" and it had been proposed by workers.

The opposition-dominated National Assembly, which Guaido heads, will start meeting public sector employees on Wednesday, he tweeted.

The plans include legislation to protect the employees from political pressure to back Maduro, local media reported.

Guaido also promised union representatives that an "amnesty" would be granted to employees who turn against the president.

The opposition leader has made a similar offer to the army. Hundreds of soldiers have defected and crossed into neighbouring Colombia.

Guaido returned to Caracas on Monday after a 10-day Latin America tour aimed at mustering support for his campaign to bring humanitarian aid to Venezuela, oust Maduro, and stage fresh elections.