CARACAS - Venezuelan President Nicolas Maduro on Tuesday criticized the US government as "childish" in conducting its foreign policy after US National Security Adviser John Bolton's notepad with words "5000 troops to Colombia" evoked concerns.

"This is a childish way to direct foreign policy from the White House," Maduro said as he led military exercises at an air force base in the north-central Venezuelan state of Aragua amid heightened tensions between the two countries.

Bolton, while announcing a new round of sanctions against Venezuela and its state oil company Petroleos de Venezuela, S.A. (PDVSA) at a press conference Monday, carried a notepad under his arm with the words scribbled on the top of a largely blank page.

Maduro said the United States appears to be relying on "psychological warfare" in its push to oust him from power.

The White House has repeatedly said "all options are on the table," hinting at a military option against Venezuela with the aid of Colombia, which is a US ally and neighbors Venezuela.

The US sanctions announced Monday aim to block the Venezuelan government's access to $7 billion belonging to the PDVSA, which the US Treasury described as "a primary source of Venezuela's income and foreign currency," and could lead to losses of up to $11 billion over the next year.

"That's why I say nerves of steel, calm and levelheadedness, confidence in our strength and maximum military mobilization," said Maduro while addressing the armed forces to boost its morale.

Maduro was reelected in the May presidential elections with 67.84 percent of the vote, and was sworn in as president on Jan 10 for another six-year term.

Alleging that the Maduro administration is illegitimate, Juan Guaido, head of the Venezuelan National Assembly, declared himself interim president during an anti-government rally on Jan 23.

The United States, Brazil and some other countries have recognized Guaido's presidency, with US President Donald Trump warning that "all options are on the table." Maduro, in response, cut diplomatic and political ties with the United States.