In a further deterioration of diplomatic ties between Venezuela and the US, President Nicolás Maduro announced on Saturday that he will curb the number of US diplomats allowed to work in the country and will impose mandatory visas for Americans travelling to the socialist nation.

Maduro also said that any meetings between US diplomats and Venezuelans would have to be “authorised” by the Venezuelan government.

The president said he decided to require visas for US citizens after the capture of an American pilot of Latin American descent in the state of Táchira, in western Venezuela. He said the pilot, whom he did not identify, was suspected of spying – though he did not provide details.

Maduro has accused the US of working with groups critical of his government to plot a coup against him, charges Washington has denied.

“Conspirator meetings are over,” Maduro said in a public speech marking the anniversary of street riots in 1989, known as the Caracazo, that left as many as 3,000 dead.

As he announced the measures, a cheering crowd clad mostly in red chanted: “Maduro, Maduro, hit the Yankee hard.”

The two countries have not exchanged ambassadors since 2010.

In addition, Maduro named US politicians who would be barred from entering the country. The list included former president George W Bush, former vice-president Dick Cheney, former CIA director George Tenet and several lawmakers who have been critical of the Venezuelan government.

“We will prohibit visas for individuals who want to come to Venezuela who have violated human rights and have bombed Iraq, Syria and Vietnam,” said Maduro.

The move was made in retaliation for targeted sanctions imposed by the US against Venezuelan officials and their immediate family members who are deemed responsible for human rights abuses and corruption. The sanctions include denying visas and freezing US-held bank accounts.

Carlos Romero, an international relations analyst in Caracas, said the measures announced by Maduro were extreme and would likely bring some sort of reciprocal measure from the US.

“We are entering a new phase of already deteriorating relations that is much more negative,” he said, warning that the next step may be a severing of diplomatic ties altogether.

“This is going to snowball,” Romero predicted.

The announcement of the diplomatic sanctions came on the same day that four American missionaries who were detained for questioning earlier in the week were released and headed home.

It also coincided with a day of marches of both government supporters and supporters of the opposition, who denounced the arrest on 19 February of Caracas mayor Antonio Ledezma, on charges of plotting a coup along with two other opposition leaders who called on Maduro to step down and pave the way for a transitional government.

Venezuela’s government is battling growing discontent among its 30 million citizens over food shortages and spiralling inflation, while the price of Venezuelan crude – the country’s lifeblood – continues to fall.

Protests in the western city of San Cristóbal last week left a 14-year-old boy dead, heightening tensions.