Washington — A bipartisan group of senators introduced legislation Wednesday to authorize $400 million in humanitarian aid to crisis-stricken Venezuela and intensify the U.S. campaign to isolate the increasingly authoritarian government of Nicolás Maduro, who has held on to power despite international pressure for him to step down.

The bill, spearheaded by Senate Foreign Affairs Committee ranking member Sen. Bob Menendez, also directs the State Department to work with European governments to replicate U.S. efforts and issue their own sanctions. The New Jersey Democrat, a longtime leader of U.S. foreign policy in Latin America, said "internationalizing" sanctions would increase pressure on the Maduro regime and its chief allies around the world.

"That is something that would be incredibly powerful, knowing that the sanctions that would levied are not just by the United States against the Maduro regime, but internationally," Menendez told CBS News during a conference call with reporters Wednesday. "That's something that could significantly change the dynamics."

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"It sends Maduro a message, as well as Russia and China that are helping to prop up Maduro," he added, referring to the Chinese government's investments in Venezuela and Moscow's military and political support for the South American country's socialist government.

Fourteen lawmakers signed on as sponsors of the legislation, known as the "Venezuela Emergency Relief, Democracy Assistance, and Development Act of 2019," or "VERDAD Act," the Spanish word for truth. Sens. Marco Rubio, Ted Cruz and John Cornyn are among the Republican sponsors of the bill, with Democratic Sens. Dick Durbin, Ben Cardin and Tim Kaine also lending support.

In addition to doubling the Trump administration's $200 million humanitarian assistance pledge to the people of Venezuela, the legislation instructs the U.S. government to devise a strategy to investigate and repurpose the assets of the Venezuelan government and its officials.

The bill, if enacted, would also impose visa restrictions on family members of high-ranking officials within the socialist Venezuelan government. The officials would be allowed to request a waiver to the restrictions on their families' travel if they have not been involved in human rights abuses and if they vouch their support for National Assembly Juan Guaidó, the U.S.-backed opposition leader.

Maduro's government has recently escalated its efforts to fend off the leadership challenge by Guaidó, who is supported by the Trump administration and more than four dozen countries. On Tuesday, the Constituent Assembly, a pro-government legislative body, voted to strip the 35-year-old opposition leader of his parliamentary immunity, which could make his arrest easier.

The chief of justice of the Maduro-allied Supreme Court has called on Guaidó to be prosecuted for violating a travel ban issued by the 35-member tribunal earlier this year. The opposition leader was also barred from public office for 15 years by the government's comptroller, who alleged Guaidó received funds from unauthorized sources and lied in his financial disclosures.

Menendez, who called the Constituent Assembly "illegitimate," said the recent moves by Maduro's government raise concerns about Guaidó's safety and suggest the regime may try to arrest him. "We have to take that rather seriously, and the world has to take it seriously."

Once one of Latin America's wealthiest economies, oil-rich Venezuela has been grappling with mounting inflation and food and medicine shortages for the past couple of years under Maduro's administration, which blames U.S.-led sanctions for the country's economic woes. The dire situation has led to persistent civil unrest and prompted more than 2.3 million Venezuelans to flee the country since 2014, according to Human Rights Watch.

Despite a growing coalition of governments calling for him to relinquish power, Maduro has managed to cling to power and secure the loyalty of the country's military.