At least seven explosions and low-flying aircraft were heard around 2 a.m. local time in Caracas. The southern area of the capital, near a major military base, was left without electricity.
Venezuelan Foreign Minister Yván Gil announced that President Maduro has signed a decree declaring a state of emergency and ordered all national defense plans to be implemented. The ministry said Venezuela "has been subjected to military aggression by the United States" and condemned attacks on civilian and military installations.
"The purpose of this attack is to seize Venezuela's strategic resources, in particular its oil and minerals," the Foreign Ministry said in a statement. "They will not be able to achieve this."
Colombian President Gustavo Petro called for an emergency meeting of the United Nations and the Organization of American States. "Caracas is under attack right now. Warn the whole world: Venezuela is under attack. They are bombing with missiles," Petro wrote on social media.
According to CBS News, Trump gave the military the green light to conduct land strikes days before the operation. Military officials had considered launching the mission on Christmas Day, but airstrikes in Nigeria against ISIS targets took precedence.
The Pentagon referred all requests for comment to the White House.
The strikes follow months of U.S. military buildup in the region, with approximately 15,000 troops and 11 naval vessels, including the USS Gerald R. Ford aircraft carrier, positioned in the Caribbean.