Washington (CNN) President Donald Trump struck a nakedly political tone during a Thanksgiving call with US service members stationed around the world as he steered the conversation toward controversial political topics.

Speaking with a US general in Afghanistan, Trump likened the fight against terrorists to his efforts to prevent a group of migrants from illegally entering the United States, and he assailed federal judges who have ruled against his administration. The President also pressed the commanding officer of a Coast Guard ship in Bahrain on trade before touting his trade policies and arguing that "every nation in the world is taking advantage of us."

US Presidents have traditionally called troops stationed abroad during the holidays to boost morale and remind the country of their service, making Trump's rhetoric yet another striking break from the norms of presidential behavior. After the call wrapped, Trump entertained more than two dozen questions from reporters and once again discredited a CIA assessment about the killing of Washington Post journalist Jamal Khashoggi.

"This was, sadly, predictable and avoidable," said retired Rear Adm. John Kirby, a CNN military and diplomatic analyst. "The President's conduct on that call, the manner in which he politicized it, demonstrated an utter and complete disregard for what military service means."

Trump has not shied away from politicizing the military in the past, and on Thursday, he drew on US men and women in uniform to justify his controversial deployment of nearly 6,000 US troops to the southern border. Without evidence, he painted Air Force Gen. David Lyons as a proponent of his hardline immigration policies after Lyons said US troops are fighting in Afghanistan to prevent terrorists from reaching "our shores again."

"Large numbers of people are forming at our border and I don't even have to ask you, I know what you want to do, you want to make sure that you know who we're letting in. And we're not letting in anybody essentially because we want to be very, very careful," Trump said, speaking to Lyons over the phone. "You're right, you're doing it over there. We're doing it over here."

The topic brought Trump to another familiar airing of grievances, as he complained over the phone to the general that the Ninth Circuit Court of Appeals has "become a big thorn in our side."

"It's a terrible thing when judges take over your protective services, when they tell you how to protect your border. It's a disgrace," Trump said. "It's a disgrace."

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Earlier this week, a judge from the Northern District of California -- where cases get appealed to the 9th Circuit -- issued a temporary restraining order blocking the Trump administration from barring migrants who cross into the US illegally from seeking asylum.

After the call wrapped, Trump continued to focus on the 9th Circuit and his administration's efforts to prevent the group of migrants -- many of whom are seeking asylum -- from crossing into the US illegally.

As he continued to lambaste 9th Circuit rulings that have skewed against him, Trump called on Congress to "get together and stop it." And he threatened to shut down the entire US-Mexico border over the approach of the few thousand migrants.

"If we find that it gets to a level where we are going to lose control or our people are going to get hurt, we will close entry into the country for a period of time until we can get it under control," Trump warned. "The whole border."

Trump also once again undermined the CIA's assessment that Saudi Crown Prince Mohammed bin Salman was responsible for the murder of Khashoggi, insisting the agency did not conclude bin Salman was responsible.

"They have not concluded. Nobody's concluded. I don't know if anybody's going to be able to conclude that the crown prince did it," Trump said. "They said he might have done it. That's a big difference."

Trump continued to defend his decision not to blame the crown prince or issue more severe punishments on a series of false or unsubstantiated claims, suggesting diminished relations with Saudi Arabia would cause "a global depression," result in the loss of "hundreds of thousands of jobs" and leave Israel defenseless.

Trump also defended his daughter, Ivanka, after it emerged earlier this week that she had used a private email account to discuss or relay official White House business, a practice evocative of the one for which Trump harshly criticized Hillary Clinton during the 2016 campaign.

He called her use of personal email -- which appears to have violated federal records laws -- "very innocent" and dismissed the comparison to Clinton, saying his daughter's private emails contained no classified information and were never deleted.

At one point, Trump was asked what he was most thankful for on this Thanksgiving.

"For having a great family and for having made a tremendous difference in this country," Trump said. "I've made a tremendous difference in the country. This country is so much stronger now than it was when I took office that you wouldn't believe it."