And those ties have been called into question over his lack of a tough response to Riyadh since journalistJamal Khashoggi disappeared and was possibly killed at the Saudi consulate in Istanbul.

"Having a President with global business ties means we've got ongoing worries that policy is going to be affected by his business interests," Robert Weissman, president of Public Citizen, which tracks potential conflicts of interest in the Trump administraition, recently told CNN .

"We know that historically the Saudis have spent huge money on Trump properties and we know that since he became a candidate and was elected they have targeted discretionary spending at his hotels," Weissman added.

Here are some of Trump's ties to Saudi Arabia.

In 1991, Trump sold his 282-foot yacht named "The Trump Princess" to a Saudi billionaire for $20 million.

Associated Press

At the time, Trump was almost bankrupt and looking to make some fast cash, reportedly selling the yacht toPrince Alwaleed bin-Talalfor one third less than he paid for it.

In 1995, Trump also sold New York City's Plaza Hotel toAlwaleed andSingaporean investors for $325 million.In turn, they sold it nearly a decade later for $675 million. In July, Alwaleed's Kingdom Holding Company re-purchased the Plaza along with a New York-based firm.

In November 2017, Crown Prince Mohammed bin Salman, also known as MBS, launched a supposed anti-corruption purge largely seen as a consolidation of his power, arresting several Saudi princes and business leaders.

Alwaleed was one of those MBS had detained, forced to stay at Riyadh's Ritz-Carlton for 83 days. You can read more about that here .

In 2001, Trump sold the 45th floor of Trump World Tower to the Saudi court for $4.5 million. In 2008, the floor became part of the Saudi mission to the United Nations.

Casper Moller via Wikimedia Commons

The New York Daily News revealed the sale in September 2016 after Trump had attacked Hillary Clinton on the campaign trail forthe Clinton Foundation accepting money from Saudi Arabia.

"Crooked Hillary says we must call on Saudi Arabia and other countries to stop funding hate," Trump wrote on Facebook in June 2016. "I am calling on her to immediately return the $25 million plus she got from them for the Clinton Foundation!"

But earlier, at a 2015 rally in Alabama, Trump had said: "Saudi Arabia — and I get along great with all of them. They buy apartments from me.

"They spend $40 million, $50 million. Am I supposed to dislike them? I like them very much," Trump added.

After announcing his presidential candidacy, Trump incorporated several companies with names indicating that they may do business in Saudi Arabia, such as "THC Jeddah Hotel Advisor LLC." Jeddah is the second largest city in Saudi Arabia.

Associated Press

After he was elected, Trump's company, the Trump Organization, announced that it had shut down those companies.

Source: Buzzfeed News , CBS

Since Trump took office, the Saudi government has also been a major customer of the presidents hotels in New York and Washington DC.

Gabriella Demczuk/Getty

Between October 2016 and March 2017,MSL Group Americas, alobbying group working for the Saudi government, spent $270,000 at Trump International Hotel in DC for lodging, catering and parking.

MSL Group Americas paid for 500 rooms for six groups of US military veterans to lobby Congress against the Justice Against Sponsors of Terrorism Act, which had passed in September, according to a report from the Washington Post on Wednesday.

JASTA would allow families of the Sept. 11 victims to sue the Saudi government, which some argued was partly responsible for the attack, since 15 of the 19 hijackers were Saudi citizens.

The veterans told the Post that the lobbying group told them that JASTA might cause other countries to prosecute US veterans for their actions in overseas war, and some said they were unaware they were sent to DC to lobby on behalf of the Saudi government.

The lobbying group said that they informed, through one way or another, the veterans that everything was paid for by the Saudi government, and that they did not book the rooms at Trump's hotel to gain favor with the incoming president, the Post reported.

In June 2017, the Trump Organization announced it would donate all profits from the sales to charity.

In March 2018, the Trump organization said it had donated$151,470 to charity, but ethics experts have challenged the company's calculations of the actual profits.

Also in March 2018, members of Crown Prince Mohammed bin Salmans entourage stayed at the presidents Trump International Hotel in New York, which caused the hotels quarterly profits to go up 13 percent.

Associated Press

The Maryland and DC Attorneys general have since filed suit against the president , arguing that the transactions could also violate the Constitution's emoluments clause, which prohibits federal officeholders from receiving anything of value from a foreign state.

Source: Washington Post

In 2017, Saudi Arabia said it would invest $20 billion in a US infrastructure fund before Trump unveiled a $200 billion plan to fix the USs roads, airports and more.

Associated Press

Blackstone CEO Stephen Schwarzman, who visited Saudi Arabia with Trump in 2017, has since withdrawn from an investment meeting in Saudi Arabia planned for next week.

Trump has also intimately engaged with the Saudi court in other ways, including participating in a traditional sword dance known as ardah.

Official White House Photo by Shealah Craighead

In May 2017, Trump simultaneously touched an odd glowing orb with Saudi King Salman and Egypt's President Sisi, which reportedly symbolized their intentions to combat exremism.

Source: CNN

Trump has also said that the US cannot rescind on its $110 billion arms deal, $14.5 billion of which has gone through to Saudi Arabia, arguing that Riyadh would just turn to China or Russia.

AP Photo/Evan Vucci

The US had already faced criticism for the arms deal over the Saudi-led coalition's execution of the war against Iranian-backed Houthis in Yemen, which has become one of the worst humanitarian disasters in the world.

Source: CNN

Saudi Crown Prince Mohammed bin Salman and Trumps son-in-law and senior adviser, Jared Kushner, have also formed a cozy relationship as they have discussed initiatives to reshape the Middle East since Trump was elected.

REUTERS/Jonathan Ernst

You can read more about that here and here .

But Trump has denied any financial ties to the Saudi court.

AP Photo/Evan Vucci

"For the record, I have no financial interests in Saudi Arabia (or Russia, for that matter)," Trump tweeted on Tuesday."Any suggestion that I have is just more FAKE NEWS (of which there is plenty)!"

See Also:

• Turkey’s Khashoggi probe moves closer to Saudi crown prince with arrest warrants for 2 of his former aides
• A friend of Jamal Khashoggi is suing an Israeli spyware firm for allegedly helping Saudi agents hack his phone
• Chinese state media hailed the trade war ceasefire between China and the US as a win for Xi Jinping

SEE ALSO: The meteoric rise of Saudi's powerful Crown Prince Mohammed bin Salman, who is now suspected of ordering the assassination of journalist Jamal Khashoggi