Updated Wednesday at 10:55 a.m. with letter from McCaul and Castro.

WASHINGTON — Dismay is growing in Congress over President Donald Trump's push to lift penalties on ZTE, the giant Chinese phone maker that violated sanctions on Iran and North Korea and then lied about its actions.

On Wednesday, House Homeland Security chairman Michael McCaul, an Austin Republican, joined with Rep. Joaquin Castro, D-San Antonio, issued a terse letter to Trump urging him to reconsider his lifeline to the firm, which faces ruin after the Commerce Department imposed a seven-year ban last month on buying U.S. components it needs to make phones and other products.

"The penalties you seek to lift were imposed after ZTE violated U.S. law sanctioning exports of certain items to Iran and North Korea," they wrote. "Lifting these penalties that were instituted after a law enforcement process would undermine the credibility of United States sanctions and permit ZTE, an entity with ties to Chinese military and intelligence agencies, access to U.S. components and technology, which would pose a risk to United States national security."

Trump briefly considered McCaul for homeland security secretary, and the Texan has generally defended the president, making the public chastisement remarkable.

Texas Sens. John Cornyn and Ted Cruz joined a broad coalition that issued a similarly stern warning on Tuesday.

"We urge you not to compromise lawful U.S. enforcement actions against serial and pre-meditated violators of U.S. law, such as ZTE," the senators wrote to key Trump cabinet members. "Export control and sanctions laws should not be negotiable, because fidelity to the rule of law is a key part of what distinguishes the U.S. from a country like China that is ruled by a Communist dictatorship."

Trump puzzled and alarmed lawmakers in both parties when he announced May 13 that he had ordered Commerce to reopen the ZTE case at the request of Chinese President Xi Jinping.

"As a favor to the president, I am absolutely taking a look at it," he said Tuesday, adding that he envisions a fine up to $1.3 billion and a corporate housecleaning — apparently on top of the nearly $900 billion ZTE has already been fined for its misdeeds.

ZTE's U.S. headquarters is in Richardson.

It's the nation's fourth largest seller of cellphones. It also makes telecommunications equipment that, like its phones, are viewed with suspicion by U.S. intelligence agencies. Experts suspect the Chinese have installed snooping capabilities. Last month the Pentagon barred sales of ZTE phones at military commissaries.

"What I envision is a very large fine of more than a billion dollars," Trump said. "Could be a billion-three. I envision a new management, a new board, and very, very strict security rules. And I also envision that they will have to buy a big percentage of their parts and equipment from American companies," he said.

A key House panel — controlled by Republicans — added language to a spending bill last week that would block Commerce from reviewing or renegotiating the penalties on ZTE, regardless of Trump's desires.

On Tuesday, the Senate Banking Committee voted 23-2 on an amendment to block Trump from easing sanctions on ZTE unless the administration first can certify that the company has complied with U.S. law for a year.

Tuesday's letter from senators was signed by 27 lawmakers from across the ideological spectrum, reflecting the extent to which Trump is out of step on ZTE.

Cruz is one of chamber's most outspoken conservatives. Cornyn is the deputy GOP leader and led the effort with Sen. Marco Rubio of Florida.

Judicary Chairman Chuck Grassley of Iowa, and Tom Cotton of Arkansas, also joined the push on the GOP side.

They worked with such Democrats as New York Sen. Chuck Schumer, the minority leader, moderate Joe Manchin of West Virginia, and two of the most liberal members, Kamala Harris of California and Sherrod Brown of Ohio.

Rubio vowed "veto-proof congressional action" to stymie Trump on ZTE, as part of a Trumpian early morning tweet storm in which he pilloried Trump for letting China out-negotiate him. The attacks from a fellow Republican forced the White House to defend the president's unusual stance yet again.

Sadly #China is out-negotiating the administration & winning the trade talks right now. They have avoided tariffs & got a #ZTE deal without giving up anything meaningful in return by using N.Korea talks & agriculture issues as leverage. This is #NotWinning https://t.co/5kGO3qRGfY — Marco Rubio (@marcorubio) May 22, 2018

Here is #ZTE timeline: Violated U.S. sanction laws & got caught lying & covering up. Paid $1billion fine & agreed to discipline employees. But then lied again & instead of discipline gave those employees bonuses. Now we are offering same deal of fine & employee discipline? — Marco Rubio (@marcorubio) May 22, 2018

The letter went to Commerce Secretary Wilbur Ross, Treasury Secretary Steven Mnuchin, and trade Ambassador Robert Lighthizer.

In March of last year, the company pleaded guilty to illegally shipping U.S. technology to Iran and North Korea and paid a penalty of $892 million. The Commerce Department later found that the company had violated the settlement and lied, triggering the ban imposed last month.

Trump has repeatedly defended his demand for Commerce to take a fresh look at the ZTE penalties, and did so again on Tuesday during a meeting with South Korea President Moon Jae-In.

He reiterated that Xi has put a high priority on protecting ZTE, which employs nearly 80,000 people worldwide and has all but stopped production since the penalties went into effect last month.

"The president asked me to look into it, and I am doing that," Trump said. "And don't forget, for the ones who say, oh, gee, maybe Trump is getting a little bit easy — ZTE, we closed it. It wasn't another administration. It was this administration that closed it."

He noted that ZTE depends on U.S.-made components to make most of its products, and he has couched the review as a way to protect jobs in both China and at home, and to ease the path to a broader trade deal.

"By shutting them down, we're hurting a lot of American companies, really good American companies," Trump said.

Ross seemed surprised last week at Trump's demand to reopen a case settled only weeks earlier, and resistant to treat ZTE's fate as a bargaining chip on trade rather than a straightforward enforcement matter.