SALT LAKE CITY — Jon Huntsman Jr. submitted his resignation as U.S. ambassador to Russia to the White House Tuesday and is expected to return to Utah to consider another run for governor.

He'll decide once he's back in Utah and has had an opportunity to talk with family and friends, a source told the Deseret News Tuesday, saying Huntsman is "keeping an open mind" about entering the 2020 governor's race.

A Republican who served as Utah's governor from 2005 to 2009, Huntsman has apparently seen himself as a potential candidate for some time. His resignation is effective Oct. 3.

In April, a source told the newspaper that Huntsman, appointed to the top diplomatic post in Russia by President Donald Trump in 2017, had not ruled out what would be his third race for Utah governor.

His letter of resignation comes after CNN reported Saturday that Trump and Russian President Vladimir Putin spoke last week about a replacement for Huntsman. Huntsman was expected to make a decision this fall about leaving the post.

In the letter dated Monday and addressed to Trump, Huntsman called his service in Moscow "a singular honor" and said he and his wife, Mary Kaye, "have given this sensitive assignment our very best."

He writes that, "Yet, as I have shared with you and Secretary (of State Mike) Pompeo, our desire is to return to the United States after two years to reconnect with our growing family and responsibilities at home."

Gov. Gary Herbert, Huntsman's former lieutenant governor, said he has "just great admiration for Jon Huntsman Jr. Again, we worked together as partners and did some good things."

But Herbert, who is not seeking reelection after serving as governor since Huntsman's resignation in 2009 to become President Barack Obama's U.S. ambassador to China, has already backed Lt. Gov. Spencer Cox to succeed him.

"I think he's certainly demonstrated his ability and his talent," Herbert said of Cox, a former state lawmaker from Fairview. "He comes to the position very well prepared and has the experience that is second to none."

Cox said Tuesday he's "a big fan of Gov. Huntsman. I always have been, and the Huntsman family. They're a critical part of Utah," adding he never anticipated he'd be running for governor himself.

"Of course, I come at it very differently. I'm not one of the three elite families in Utah. I come from the middle of nowhere on a small farm," Cox said, adding he believes he can beat Huntsman for the nomination.

A recent poll for the Salt Lake Chamber showed Huntsman trailing Cox among Republican voters in the race for governor. Cox is the first declared candidate in the race.

Other possible candidates include Greg Hughes, a former Utah House speaker; Spencer P. Eccles, former head of Herbert's economic development office; Greg Miller, son of Utah Jazz owner Gail Miller; Salt Lake County Councilwoman Aimee Winder Newton; retiring Utah Rep. Rob Bishop; and former Utah GOP Chairman Thomas Wright.

Huntsman is the son of the late Utah billionaire philanthropist Jon Huntsman, while Eccles and Miller are also the sons of prominent contributors to community causes in Utah.

"We've got good people to choose from," Herbert told guest host Kirk Jowers on KSL Newsradio Tuesday after the news of Huntsman's resignation became public. "They're all going to have to get out there and acquit themselves."

Jason Perry, head of the University of Utah's Hinckley Institute of Politics and a former economic development director under Huntsman, said if Huntsman does enter the race, he'll have an immediate impact because of his past popularity.

Perry said Huntsman could also help shape the tone of the race because of his experience in the office.

"I think this race will become largely about policy," Perry said. "That is an ideal situation for a political race where it becomes not just about politics but about the direction for the state of Utah."

FILE - Ambassador Jon M. Huntsman Jr. walks in Moscow, Russia on Wednesday, Sept. 26, 2018, on his way to work at the Embassy of the United States of America.
FILE - Ambassador Jon M. Huntsman Jr. walks in Moscow, Russia on Wednesday, Sept. 26, 2018, on his way to work at the Embassy of the United States of America. | Ravell Call, Deseret News

Huntsman was first elected governor in 2004 from a crowded Republican field, but he resigned his office a year after being reelected in 2008 to take the ambassador position in China.

The 59-year-old left that posting to run for president against Obama in 2012, but he dropped out of the race for the Republican nomination shortly after a disappointing third-place finish in the New Hampshire primary.

He has previously served as U.S. ambassador to Singapore under President George W. Bush and was a U.S. trade representative in Asia under President George H.W. Bush.

Speculation about why Huntsman may want to be governor againincludes what has been described by political observers as his long-term goal of being named U.S. secretary of state.

Being elected governor of Utah keeps him in the spotlight for such an appointment no matter who ends up being elected president in 2020, since Huntsman has worked for both Democratic and Republican administrations, observers say.

"I think there's no one better qualified to be secretary of state than Jon Huntsman," Jowers, a former Hinckley Institute leader, said. "But governor, especially of Utah, is a great post."

Jowers questioned whether it would be a negative for Huntsman to run for governor while hoping to be named secretary of state, comparing him to a former U. football coach who led the Utes to national success before moving on to bigger teams.

Ambassador Jon M. Huntsman Jr. talks with his wife, Mary Kaye, at the Spaso House, where they live, in Moscow on Saturday, Sept. 22, 2018.
FILE - Ambassador Jon M. Huntsman Jr. talks with his wife, Mary Kaye, at the Spaso House, where they live, in Moscow on Saturday, Sept. 22, 2018. | Ravell Call, Deseret News

"I'm really grateful as a fan of the University of Utah that Urban Meyer used us as a stepping stone," he said. "Sometimes the best thing that can happen for a state — or a college football program — is to be used as a stepping stone because you get the very best."

Fred Kempe, president and CEO of the Atlantic Council, praised Huntsman's service in a KSL Newsradio interview. Huntsman was chairman of the foreign policy think tank based in Washington, D.C., before joining the Trump administration.

"Obviously, he’s one of our top diplomats ever," Kempe said of Huntsman, possibly the only U.S. ambassador to both China and Russia. "It's a real loss for the American foreign service. But he’s had two hard years."

Huntsman said in his resignation letter that the United States "must continue to hold Russia accountable when its behavior threatens us and our allies. While much of what divides us is irreconcilable, there are common interests we cannot ignore."

He said through the embassy's diplomacy, "We have worked to stabilize years of acrimony and incertitude with the hope of a better relationship. Failure is not an option, and the people on both sides deserve better."

Talk must continue, he said, "on issues of national interest — combatting terrorism, ensuring verifiable arms control, insisting that Russia respect the sovereignty of its neighbors and advocating for a more responsive system of governance that includes rule of law and respect for human rights."

October marks two years in Moscow for Huntsman, longer than he was in Beijing.

Huntsman's daughter, Abby, a co-host on ABC's "The View," tweeted, "Two years away from family, working tirelessly to help our most challenging relationship during an incredibly difficult time in history … my dad is a true patriot who loves this country. Excited to get him back home! A new chapter begins "

Her co-host on the daytime talk show, Meghan McCain, the daughter of the late Arizona Senator John McCain, responded on Twitter, "Your father @JonHuntsman is one of the great diplomats and patriots of our time — we are all so grateful for his service to this incredible country of ours."