(CNN) President Donald Trump, mulling how to end the US role in the Syrian conflict while having other countries "take care of it," has maintained an unusual fixation: the jumbo jets owned by Persian Gulf monarchs.

"Without us you wouldn't last two weeks. You'd be overrun. And you'd have to fly commercial," Trump told one Gulf leader recently in a conversation he boasted about later to friends.

As the President's national security team prepares options for Syria, advisers and officials say economic factors -- rather than a concern for global security -- have animated Trump. Even as top US military officials quietly prepare plans that would actually increase the number of US troops deployed to Syria, Trump has decided that the time has come to cut an early exit, according to people familiar with the situation.

He's increasingly pressed foreign leaders -- particularly in the oil rich Gulf states -- to step up.

Speaking to reporters in the East Room, Trump said Tuesday that he and his team were nearing a decision on how to proceed in Syria now that ISIS has lost most of its territory.

"Sometimes it's time to come back home. And we're thinking about that very seriously," Trump said, bemoaning the trillions of dollars spent on wars in the Middle East which he said resulted in "nothing except death and destruction."

"I want to get out. I want to bring our troops back home. I want to start rebuilding our nation," Trump said.

Those were views Trump first aired publicly last week during a freewheeling, campaign-style event in Ohio , where Trump inserted his declaration that "we'll be coming out of Syria, like, very soon" into a speech that was otherwise focused on a booming US economy.

The statement caused a stir back in Washington, where puzzled Pentagon and State Department officials contacted the White House to determine what, precisely, the President's position on Syria was.

Recipe for withdrawal

National security officials had been weighing for months the conditions that would need to be met before US troops withdraw from the country, where they have helping battle ISIS. Military commanders have not recommended to Trump that he order a withdrawal of US troops there, citing the persistent presence of ISIS and the power vacuum that would result if the US departs.

But he has insisted in private since at least February that he wants out of the country, multiple people familiar with the matter said. And he has lamented the expenditure of billions in US taxpayers dollars to fund a fight he says should be financed by regional players.

That's in contrast to members of his own administration, who insist the ISIS fight must continue until the terror group is eradicated. While the US and its allies on the ground have made massive gains reducing ISIS' territory, the grou is entrenched in its remaining strongholds and removing them will require continued US involvement, those national security officials have said.

Officials have also warned Trump that players like Iran, Turkey and Russia could use a US withdrawal to advance their own strategic interests in Syria. The leaders of those countries -- Iranian President Hassan Rouhani, Turkish President Recep Tayyip Erdoğan and Russian President Vladimir Putin -- are meeting this week in Ankara to discuss further steps in Syria.

"In terms of our campaign in Syria, we are in Syria to fight ISIS. That is our mission. And our mission isn't over, and we're going to complete that mission," said Brett McGurk, the special presidential envoy for defeating ISIS, said during remarks at the US Institute for Peace in Washington.

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McGurk's comments came a mere three minutes before Trump declared in the East Room that "it's time" for American troops to come home.

Gen. Joseph Votel, commander of the United States Central Command, said Tuesday the "hard part" in Syria lies ahead while speaking at the same event as McGurk.

"A lot of very good military progress made over the last couple of years, but again the hard part I think is in front of us, and that is stabilizing these areas, consolidating our gains, getting people back into their homes, addressing the long terms issues of reconstruction and other things that will have to be done," he said.

While Trump's top commanders have each individually said that now is not the time to withdraw from Syria, a person close to the White House told CNN that Defense Secretary James Mattis has avoided bringing up the issue -- beyond the fight against ISIS -- directly with the President.

That's a calculated move on the part of Mattis, who does not want Trump to associate him with an issue that he perceives as troublesome -- or at least overly complicated -- said the person. The source added there is a view within the White House that the Pentagon sees its job as destroying ISIS -- a topic Trump likes -- so there is no upside in pushing the broader Syria issue with him.

Transitional moment

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The deliberations over Syria come as Trump transitions to a national security team that's seen as more willing to agree with him on issues like troop levels and diplomatic efforts. That includes incoming national security adviser John Bolton, who is replacing H.R. McMaster next week.

Bolton is a noted hawk, though he hasn't voiced an opinion on whether to keep US troops in Syria since being named by Trump to the position last month. He was, however, an architect of the Iraq War, which Trump has used as a cautionary tale when explaining his motives in advocating a withdrawal from the region.

"We get nothing, nothing out of it, nothing," Trump said during his news conference. "For years, I said keep the oil, I was always saying keep the oil. We didn't keep the oil. Who got the oil? It was ISIS got the oil. A lot of it."

A person familiar with internal discussions on the issue told CNN on Tuesday the White House would likely push for a deal with the Gulf Cooperation Council -- a political and economic union consisting of all the Arab states in the Persian Gulf except for Iraq -- in an effort to secure territory in southern Syria so that it doesn't fall to Iran. The agreement would utilize the minimum amount of US troops possible, the person said.

This source added the White House is seeking additional assistance from Saudi Arabia, which the administration has worked to convince to send money and troops.

"Saudi Arabia is very interested in our decision, and I said, 'Well, you know, you want us to stay, maybe you're going to have to pay,' " Trump said on Tuesday.

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Trump met last month with Saudi Arabia's de facto leader, Crown Prince Mohammed bin Salman , at the White House. After their meeting, the crown prince told Time Magazine that American troops should remain in Syria "for at least the midterm, if not the long-term."

On Monday and Tuesday this week, Trump spoke with both King Salman bin Abdulaziz Al Saud of Saudi Arabia and Emir Tamim Bin Hamad Al Thani of Qatar, emphasizing to both leaders the importance of restoring a "united" Gulf Cooperation Council and thanking them for their continued cooperation on fighting terrorism.

Trump and Salman "discussed joint efforts to ensure the enduring defeat of ISIS and counter Iranian efforts to exploit the Syrian conflict to pursue its destabilizing regional ambitions," the White House said.

In his past conversations with Gulf leaders, Trump has pointed to their extravagant lifestyles -- including fleets of Boeing 747s and massive superyachts -- as evidence they have money to spare to play a bigger role in securing the region.

"Have you ever flown commercial before?" Trump asked one leader, according to a person he recounted the conversation to afterward. "He said, 'No.' And I said, 'Get used to it.' "