Bolton, speaking on "Fox News Sunday," said the incident could be "a pretext set up by the regime itself" of President Nicolas Maduro "or something else."

While denying any US role, he said that if Venezuela had "hard information" of a potential violation of US law, "we will take a serious look at it."

Maduro on Saturday described the incident -- in which explosives allegedly carried on a drone detonated as he was giving a speech -- as an "assassination" attempt.

The president and his wife escaped unharmed, though the government said seven soldiers were wounded. Maduro blamed Colombia, though a mysterious rebel group later claimed responsibility.

Bolton said he had spoken to the US charge d'affaires in Caracas and was told the embassy was secure and American staff "accounted for."

In addition to Colombia, Maduro's government cast blame on "the ultra-right wing" in Venezuela, which Bolton said "means the vast opposition to his authoritarian role."

In addition, Bolton said that Maduro "has blamed the United States," adding, "These are things he has said before and you have to take them for what they are worth."

US President Donald Trump has been harshly critical of Maduro's leftist regime, saying it has "destroyed a prosperous nation by imposing a failed ideology."

Last August, Trump alarmed Caracas by saying publicly that he could not rule out a "military option" to quell the chaos there.