Washington (CNN) Donald Trump Jr. retweeted an unsubstantiated claim on Friday insinuating missing Saudi journalist Jamal Khashoggi is a terrorism sympathizer -- a move that comes as the administration of his father, President Donald Trump, faces pressure on how to respond to the journalist's disappearance.

Khashoggi, a former Saudi royal insider who became a critic of the country's government, disappeared last week after he went into the Saudi Arabian consulate in Istanbul, Turkey, to obtain paperwork to marry his Turkish fiancée.

Turkish authorities have said they believe Khashoggi, a columnist for The Washington Post, was killed inside the consulate, a startling allegation that is firmly denied by the Saudis.

The series of tweets that Trump Jr. retweeted Friday included a post by Patrick Poole, who according to his Twitter profile is a national security and terrorism correspondent for PJ Media, a conservative-leaning collaborative news and commentary blog formerly known as Pajamas Media.

In his tweet, Poole shared images of a decades-old newspaper article written by Khashoggi about the mujahedeen.

In a photo accompanying the article, Khashoggi, a prominent journalist in the Middle East, appears beside individuals identified as members of the Islamist group and holds a rocket-propelled grenade launcher. A separate photograph in the article pictures Osama bin Laden and some of his associates. Bin Laden cofounded al Qaeda in the late 1980s.

In the tweet, Poole wrote: "I didn't realize until yesterday that Jamal Khashoggi was the author of this notorious 1988 Arab News article of him tooling around Afghanistan with Osama bin Laden and al-Qaeda co-founder Abdullah Azzam. He's just a democrat reformer journalist holding a RPG with jihadists."

Khashoggi covered al Qaeda as a foreign correspondent in Afghanistan and Sudan and was well known for his several interviews with Osama bin Laden. He distanced himself from bin Laden after the September 11, 2001, terrorist attacks. At the time of the news article posted by Poole, the United States was arming and funding the mujahedeen in the Soviet-Afghan War.

Sean Davis , co-founder of The Federalist, retweeted Poole's post with a comment claiming Iranian influence over the news media's reporting on Khashoggi, implying an effort by Iran to damage US-Saudi relations. Iran and Saudi Arabia are longstanding rivals.

"Huh. It's almost like reality is quite different than the evidence-free narratives peddled by media with a long history of cooperating with or getting duped by Iran echo chamber architects," Davis wrote on Twitter.

Trump Jr. then retweeted Davis' comment.

The Trump Organization on Friday night did not immediately return CNN's request for comment on Trump Jr.'s Twitter post.

Trail of evidence

According to a US official familiar with the intelligence, the United States has intercepts of Saudi officials discussing a plan to lure Khashoggi back to Saudi Arabia and detain him, but it is unclear if the original plan was to murder Khashoggi or if something went wrong at the consulate and that he might have been killed during an attempt to kidnap him.

A US official familiar with the latest intelligence told CNN that the "working assumption" in Washington currently is that Jamal Khashoggi was murdered inside the consulate in Istanbul.

"We are pretty clear eyed it is likely to have happened, and it didn't end well," said the official, who also cautioned that this was the latest assessment and no conclusions had been made.

However, US officials have so far declined to endorse a Turkish assessment of Khashoggi's death, which includes -- according to Turkish claims -- audio and video recordings from inside the consulate revealing Khashoggi was killed.

In the wake of the disappearance, Trump and his administration have resisted cutting ties to Saudi Arabia, a key US defense and trading partner.

Although the Saudis have issued a broad denial of responsibility, they have not offered concrete evidence to prove Khashoggi walked out of their consulate or is still alive.

US response

On Friday, Trump vowed to raise the matter with Saudi King Salman and claims that answers will come "sooner than people think," but senior administration officials described a process that could take weeks, if not months, to determine what precisely happened to Khashoggi and develop a US response if it is determined he was killed on orders from the Saudi government.

Trump has made clear that his administration will not make human rights overseas a priority; he and especially his son-in-law and senior adviser, Jared Kushner, maintain close ties to the crown prince; and Trump has long had business ties to Saudi Arabia, where he made his first foreign trip as President.

In addition, Trump has established a trio of goals in the Middle East that depend on Saudi Arabia's rulers and their money. The kingdom is central to the Trump administration's goals on Middle East peace, its effort to fight ISIS in Syria and elsewhere, and its foreign policy priority of countering Iran.

That combination of factors explains low-key US responses following aggressive Saudi foreign policy moves and the muted response to Khashoggi's suspected assassination. They also create a dilemma for the White House, as lawmakers moved Wednesday to force a showdown over US values in foreign policy by triggering a human rights probe that could lead to sanctions.

Asked in an interview with CBS's "60 Minutes" airing Sunday if he would impose sanctions on Saudi Arabia it they're shown to be responsible for Khashoggi's disappearance, Trump repeated earlier remarks that he didn't want to do something that would force US military contractors to lose an order for arms sales, a reference to billions of dollars in arms sales to the country.

"There are other ways of punishing, to use a word that's pretty harsh but it's true," he said, adding later, "We're going to get to the bottom of it and there will be severe punishment."