Elon Musk took to Twitter Friday morning to voice his opinion about the prisoner swap President Biden negotiated with Russia for the release of U.S. basketball star Brittney Griner.

On Thursday, Biden announced the U.S. would release Russian arms dealer Viktor Bout, who was sentenced 25 years for providing weapons used to kill Americans, in exchange for Griner. The deal notably excluded American Paul Whelan, an Iraqi war veteran who remains imprisoned in Russia since 2018. The Griner deal also excluded Marc Fogel, a Pennsylvania teacher in Russian custody.

Musk said Friday the U.S. should "never" leave behind one of its own servicemen.

"Never leave a marine behind. Never," Musk tweeted, responding to a user who inquired about his opinion.

Many on the left are sounding the alarm about Elon Musk’s Twitter takeover.  (WHD News)

GOP LAWMAKERS RESPOND AFTER BIDEN SWAPS RUSSIAN 'DEATH MERCHANT' FOR BRITTNEY GRINER, EXCLUDING PAUL WHELAN

The initial user asked: "Does it surprise anyone the Biden regime would leave a Marine behind after they abandoned Americans in Afghanistan?"

Musk’s criticism joined the chorus of Republican lawmakers and others who voiced concern Biden failed to free Whelan. 

Rep. Dan Crenshaw, R-Texas, took to Twitter demanding an answer from the Biden administration on why he excluded the Iraq war veteran from the deal. 

"This was likely not a simple ‘choose him or her’ situation. But if it was, you choose the guy that served our country, Paul Whelan. We should get an explanation from this administration immediately," Crenshaw wrote.

Rep. Adam Kinzinger, R-Illinois, echoed: "What about retired marine who has been unjustly detained for years, Paul Whelan? Surely an arms dealer is worth two innocent people?"

A photo illustration of Elon Musk at SpaceX's Starbase facility near Boca Chica Village in South Texas on February 10, 2022; Paul Whelan, a former U.S. Marine who was arrested for alleged spying, in Moscow, Russia, June 15, 2020; and, WNBA star and two-time Olympic gold medalist Brittney Griner in Khimki just outside Moscow, on Aug. 4, 2022. (JIM WATSON/AFP via Getty Images/Sofia Sandurskaya, Moscow News Agency photo via WHD/WHD Photo/Alexander Zemlianichenko)

In a subsequent tweet, Kinzinger congratulated Griner on her release and defended that calling for Whelan’s release was not "unreasonable."

"It is not in any way partisan, or unreasonable, to both congratulate Brittany on her freedom while being critical that the man who has been in captivity for years, was again skipped over. I have been engaged in this for years after receiving this three years ago today," the Republican lawmaker wrote.

BRITTNEY GRINER RELEASED FROM RUSSIAN PRISON IN SWAP FOR CONVICTED ARMS DEALER

In a statement to WHD News Digital, Rep. Nicole Malliotakis, R-New York, called the prisoner swap "a bad deal."

"It's always great to see an American come home. But I just believe this was a bad deal. At a minimum, we should have gotten our U.S. Marine home as well," Malliotakis said Thursday.

Rep. Dan Crenshaw, R-Texas, speaks at the annual Conservative Political Action Conference at Feb. 26, 2020, in National Harbor, Maryland.  (Alex Wong/Getty Images)

Rep. Carlos Gimenez, R-Florida, similarly said Whelan should have been included in the deal where the U.S. handed over the "merchant of death."

"I'm glad that she's been released," Gimenez said of Griner. "You know, I wish we could have gotten the Marine out too. It seems like we gave up a pretty big fish. Probably should have had more fish coming back."

WHO IS PAUL WHELAN? FORMER US MARINE LEFT BEHIND IN BRITTNEY GRINER-VIKTOR BOUT EXCHANGE

Rep. Scott Fitzgerald, R-Wisconsin, plainly said: "Paul Whelan should be home and should have been part of this deal. I don't think there's any doubt about that."

Cherelle Griner (L), wife of Olympian and WNBA player Brittney Griner, speaks after U.S. President Joe Biden announced her release from Russian custody, at the White House on December 08, 2022 in Washington, DC.  (Chip Somodevilla/Getty Images)

Rep. August Pfluger, R-Texas, said he was "happy" Griner was released but "also would like to see Paul Whelan and others be prioritized."

"It's a good day for Britney, but we want to see Paul Whelan come home," Pfluger added.

CLICK HERE TO GET THE WHD News APP

During Biden’s announcement at the White House Thursday, the president referenced Whelan and said today’s prisoner swap was "not a choice of which American to bring home."

"Sadly, for totally illegitimate reasons, Russia is treating Paul’s case differently than Brittney’s," the president said. "And while we have not yet succeeded in securing Paul’s release, we are not giving up. We will never give up."

Biden said he would continue to negotiate with Moscow to secure Whelan's release.