Or he could have secret talks with Putin where he expels all the US translators and others in the room and only allows Putin's translator, and he could cut a deal for Trump Tower Moscow, in exchange for Ukraine.
Just as Trump offered up long term US ally, Qatar, to Saudi Arabia for invasion, that is, until Qatar rethought the $2B loan to Jarad, to save his family from a catastrophic first, Trumplike bankruptcy. and instantly Trump and Saudi backed down and it was never raised again.
Every nation knows that you can get Trump on side by enriching his family, even if it means betraying allies, or trading away America's national value for no gains to the country.