The United States, most of Latin America, and the European Union recognize Guaido as interim president, while Russia, China, and Cuba back Maduro.
Lawmakers said Guaido's vehicle continued but his exact location was being kept a secret due to security concerns.
In televised comments on Thursday, Maduro said the stockpiling was a provocation.
Opposition leaders said they also plan to bring emergency supplies of food and medicine from Curacao and across the jungle-covered border with Brazil.
Guaido has set a Saturday deadline for the aid to be allowed into Venezuela.
After the Brazilian government pledged to also send aid in, Maduro declared that the Venezuelan government would close the border with Brazil on Thursday night. Opposition figures have suggested forming human chains across the Colombian border to pass packages from person to person and fleets of boats arriving from the Dutch Caribbean islands. The economy's size has halved over the past five years.
In a video shared by Bolton on Twitter, Chirinos identified himself and called Maduro's government "illegally constituted", while dressed in a military uniform and standing in front of the flags of Venezuela and the United Nations.
Meanwhile a boat carrying 250 tons of aid left Puerto Rico's capital of San Juan headed for Venezuela on Wednesday, the local government said in a statement.
Fifty countries, including Germany, have recognized Guaido as interim president since he openly challenged Maduro.
Maduro accuses the Trump administration, which has levied crippling sanctions against his government, of seeking to force his ouster.
Mr Guaido is backed by the U.S. and dozens of nations, while Mr Maduro is supported by Russia, China, Cuba, Turkey and many other countries. "How this happens depends on you, brothers in arms", he said, addressing the military.
Guaido has offered amnesty to military officers who disavow Maduro, though few have so far done so.
U.S. envoy for Venezuela Elliott Abrams has a record of using humanitarian convoys to smuggle arms to Latin American countries targeted for regime change by Washington, and Caracas says he is now trying to follow the same script in Venezuela.
The opposition leader said he has enlisted hundreds of thousands of volunteers to bring in aid in defiance of Maduro's blockade, claiming 300,000 people could perish if the blockade continues.