The 35-year-old was at an event to unveil his economic proposals when he interrupted his speech to announce that members of the Special Action Forces (FAES) were at his residence seeking his wife, Fabiana Rosales.
Guaido's wife was with him at the event, but his baby daughter was at the home with her grandmother. "I hold you responsible for anything that might happen to my baby," the opposition leader said, speaking directly to President Nicolas Maduro.
"They were harassing my family, because we know this is their modus operandi," he said.
The 35-year-old rushed home and met reporters an hour later with his daughter and wife in hand. "Today they managed to make me feel more united with Venezuelan families! We will stand firm," Guaido tweeted.
He wrote that despite the government's intimidation, born out of a fear for the plan his team had unveiled, their event was successful.
The Venezuelan police, who oversee the FAES commandos, rejected Guaido's accusation. In a tweet, the police denied having gone to his home and said the allegations were "totally false."
The opposition leader said he had sent communications to both Russia and China, Maduro's top foreign creditors and political supporters. Guaido said he had made a good case for them to support his government.
"What most suits Russia and China is the country's stability and a change of government," he said. "Maduro does not protect Venezuela, he doesn't protect anyone's investments, and he is not a good deal for those countries," the self-declared interim president added.
US offers aid
A US official said on Thursday that Washington would offer humanitarian aid to Guaido whenever he sought it. Nicolas Maduro has so far rejected the delivery of medicine, food and other basic goods from both the US and the UN.
Guaido responded saying he planned to defy the government bans and bring the humanitarian assistance with the help of neighboring nations.
"In a few weeks they will have to choose if they let much needed aid into the country, or if they side with Nicolas Maduro," the 35-year-old said of the country's military, which controls all of Venezuela's ports.