Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Venezuelan President Nicolás Maduro said his government was breaking relations with the United States and gave diplomatic personnel 72 hours to leave the country after President Donald Trump on Wednesday backed the country's opposition leader, Juan Guaidó, as interim president.

Hours later, Secretary of State Mike Pompeo issued a statement saying the U.S. does not recognize the Maduro regime as the country's government. "Accordingly the United States does not consider former president Nicolas Maduro to have the legal authority to break diplomatic relations with the United States or to declare our diplomats persona non grata."

Guaidó, 35, the leader of the opposition-controlled National Assembly, had earlier declared himself interim president as hundreds of thousands marched in Caracas demanding an end to Maduro's government.

In a statement, Trump said: "In its role as the only legitimate branch of government duly elected by the Venezuelan people, the National Assembly invoked the country’s constitution to declare Nicolás Maduro illegitimate, and the office of the presidency therefore vacant."

"The people of Venezuela have courageously spoken out against Maduro and his regime and demanded freedom and the rule of law," stated Trump.

In a briefing call, a senior administration official told reporters that all options are on the table if any actions are taken against Americans or U.S. interests — or violence against Guaidó.

Actor @edgarramirez25 attends Venezuela protests in NYC, reacts to interim president Juan Guaidó: "The international community is with us, everyone in Venezuela is supporting democracy, so we're very happy."



Details ➡️https://t.co/kmqjyRWY6t pic.twitter.com/V1mFb94Jlv — NBC Latino (@NBCLatino) January 23, 2019

The official emphasized economic actions, saying they had only begun to scratch the surface. Later he said if Maduro resorts to violence, they have no future - and that will be their last days.

Most countries in Latin America, as well as Canada, recognized Guaidó as interim president after he took the oath before his supporters. Leftist allies, Cuba and Bolivia, were the only two in the region that voiced support for Maduro. Mexico's new leftist president Andres Manuel Lopez Obrador said he would not take sides and said support for Guaidó is a violation of sovereignty.

The Morning Rundown Get a head start on the morning's top stories. This site is protected by recaptcha

“This needed to happen,” said Israel Larez, 51, at the opposition rally. “To me, he became the legitimate president weeks ago. He just needed ‘su juramentacion,’ — his swearing in," he said as he thanked the international community.

At the rally on Wednesday in Caracas, people shouted: “Who are we? Venezuela! What do we want? Freedom!” as they held Venezuelan flags.

Venezuela’s opposition filling streets nationwide today in protests against President Maduro and his socialist government. pic.twitter.com/IjzXdd6aOh — NBC News (@NBCNews) January 23, 2019

Edwin González, 24, a university student studying engineering, came out to march because he said it was Venezuelans last chance to “get rid of the regime.” He said he has participated in almost every anti-government protest in the past.

“We have no other choice but to protest,” said González. “They have taken everything away from us, even fear.”

The protests, which were joined by rallies in other countries, including the U.S., Spain and Lebanon, were called to coincide with the anniversary of the 1958 coup that overthrew military dictator Marcos Pérez Jiménez — a historic date for Venezuelans.

Maduro was inaugurated two weeks ago to a second, six-year term, which the U.S. and dozens of other countries have called illegitimate.

Venezuelan President Nicolas Maduro speaks to a crowd of supporters flanked by his wife Cilia Flores, Venezuelan Vice-president Delcy Rodriguez, the head of Venezuela's Constituent Assembly Diosdado Cabello, along with other members of the government, during a rally in Caracas on Jan. 23, 2019. Luis Robayo / AFP - Getty Images

González said his university has suspended classes because it has not had running water for 55 days. Despite protesting to have the water restored, “like all government issues, they don’t work,” he said.

González, however, does not want to emigrate. “I have lived my entire life under dictatorship. I would like to see something new.”

Opposition supporters are tear gassed as they take part in a rally against Venezuelan President Nicolas Maduro's government on Wednesday. Manaure Quintero / Reuters

The socialist leader Hugo Chávez was elected in 1998 and used revenues from the oil boom to spend heavily on social programs. He died in 2013 just before oil prices dropped sharply and Maduro took over.

Since then, the oil-rich nation has spiraled into economic and political turmoil and is nearing total collapse. Hyperinflation has made its currency, the bolivar, practically worthless. Severe shortages in food and medicine have left Venezuelans hungry and dying of preventable diseases. Crime, often fueled by poverty, is rampant. Over 3 million Venezuelans have fled the country, straining the resources of nearby nations.

Government supporters also marched in Caracas in what was supposed to be a rival show of strength. It attracted thousands but was far smaller than the opposition march.

Juan Guaido greets supporters after declaring himself Venezuela's interim president during a rally against Nicolas Maduro in Caracas on Wednesday. Federico Parra / AFP - Getty Images

During the rally, Socialist party leader, Diosdado Cabello, called on government supporters to mobilize in front of the presidential palace and protect Maduro. He said there is a U.S.-led conspiracy to remove Maduro from power.

One of Maduro's supporters was Javier Terán, 43, who works for the Oil Ministry.

“I am here to support continuity and the presidency of Maduro. The people elected him,” he said at the pro-government march. “Our people have been attacked internally and externally since Chávez was in power.”

Terán added that current right-wing governments in neighboring countries are "attacking" Venezuela economically and psychologically.

Frank Mora, a former Pentagon official in the Obama administration who now heads Florida International University’s Latin America and Caribbean Center, cautions this can go in a number of different directions, since it is a volatile situation.

He cautions that Washington and other countries could be “boxing themselves in,” explaining that everyone is betting there will be a violent confrontation and the military will turn on the government.

FOLLOW NBC LATINO ON FACEBOOK, TWITTER AND INSTAGRAM.