CARACAS, Venezuela — The Trump administration is warning that it might impose more sanctions on Venezuelan officials over President Nicolás Maduro’s push to rewrite the constitution amid an escalating political crisis with near-daily demonstrations calling for his ouster.

“What President Maduro is trying to do yet again is trying to change the rules of the game,” Michael Fitzpatrick, deputy assistant secretary of state for Western Hemisphere affairs said Tuesday. “The actions that were taken yesterday may well give us new reasons for considering additional individualized sanctions.”

The warning comes as pressure is building on the Trump administration from Congress to act more forcefully to rein in Maduro. On Wednesday, a bipartisan group of senators says it will introduce legislation providing humanitarian assistance to Venezuela while toughening sanctions against corrupt officials, according to Senate aides who spoke on condition of anonymity.

The legislation, a copy of which was obtained by press agencies, also instructs the intelligence community to prepare a partly unclassified report on Venezuelan government officials’ involvement in corruption and drug trafficking.

Opposition leaders called for a major march Wednesday in Caracas, seeking to keep the heat on Maduro after a month of unrelenting protests. On Tuesday, protesters disrupted traffic in the capital by blocking streets with broken concrete, twisted metal and flaming piles of trash. Police used tear gas to scatter demonstrators as they have almost every day for weeks.

Maduro began the week by signing a decree to begin the process of rewriting Venezuela’s constitution, which was pushed through in 1999 by his predecessor and mentor, the late President Hugo Chávez.

Opposition leaders called the planned constitutional assembly a ploy to keep Maduro and his allies in power by putting off regional elections scheduled for this year and a presidential election that was to be held in 2018. Opinion polls have suggested the socialists would lose both elections badly at a time of widespread anger over triple-digit inflation and shortages of food and other goods.

The proposed U.S. legislation, written before Maduro’s latest move, is co-sponsored by Sen. Ben Cardin, the top-ranking Democrat on the Senate Foreign Relations Committee, and Sen. Marco Rubio, the author of earlier sanctions legislation on Venezuela. It also has the support of Sen. John Cornyn, the chamber’s No. 2 Republican, former Democratic vice presidential nominee Tim Kaine, as well as Republican Sen, John McCain, chairman of the Senate Armed Services Committee.

The U.S. already has sanctioned several Venezuelan officials, including, in February, Vice President Tareck El Aissami, for allegedly being a major cocaine trafficker.

The new legislation seeks to put into law executive action by the Obama administration that targeted officials involved in corruption and found to “undermine democratic governance” with sanctions freezing any U.S. assets and banning them from entry into the U.S.

It also would mandate $10 million a year in humanitarian assistance to Venezuela. Maduro has rejected such aid offers as attempts by the U.S. to pave the way for foreign intervention.

It also calls on the Trump administration to “take all necessary steps” to prevent Rosneft from gaining control of critical U.S. energy infrastructure. The Russian government-controlled company is a major creditor to Venezuelan state-run oil giant PDVSA and recently took a nearly 50 percent stake in its U.S. subsidiary, Citgo, as collateral for a new loan.

South American governments have criticized Maduro’s move in stronger language than they have used so far for his government, with Brazil calling the decree a “coup.” And Venezuela’s foreign minister came away empty-handed after seeking support at Tuesday’s meeting of the left-leaning Community of Latin American and Caribbean States.

Although he has hinted that some members of the constitutional assembly will be chosen by voters, Maduro has given no details on how the body might be picked, leading many to predict the selection process will favor the socialists.

The president said Tuesday that he hoped the opposition would join in the process of creating a new constitution.

“They don’t realize how lost they are in their violence. I’m extending my hand and asking them to come to the constitutional convention,” he said.

Venezuela’s congress, which has an opposition majority, ignored that Tuesday, officially rejecting the idea of holding a constitutional assembly. It said Venezuelan voters should decide whether to call one, though the rejection was a symbolic gesture because congress has no power to block such a gathering.

Venezuela’s constitution was last rewritten in 1999, early in Chávez’s 14-year presidency as he launched a socialist revolution in this oil-exporting nation. Chávez called his new constitution the best in the world, predicting it would last centuries. He carried around a blue pocket-size version of the charter, and would often whip it out and say: “This is our Bible. After the Bible, this.”

At least 29 people have died in the unrest of the past month and hundreds have been injured. On Tuesday, the government suspended for 180 days the right to carry guns. The unrest erupted after an attempt to nullify the powers of the opposition-controlled, but a growing number of people have joined to show their anger over Venezuela’s economic ruin and violent crime.

HANNAH DREIER

JOSHUA GOODMAN