(CNN) - President Donald Trump isn't doing Congress any favors when it comes to figuring out how to avoid a partial government shutdown in nine days.
"I don't know what his plan is," John Cornyn, the No. 2 Senate Republican, told CNN Thursday, as Congress searches for a budget resolution that appeases both Trump and the handful of Senate Democrats needed for passage.
On Tuesday, the President clashed with Democratic leaders over $5 billion in funding a US-Mexico border wall he said he wants as part of an agreement to keep the government open. Even though his party still retains control of Congress until the end of the year, Senate Democratic votes are needed to pass a budget.
But on Thursday morning, Trump said the new US trade agreement with Mexico and Canada would be the source of the wall's funding.
"I often stated, 'One way or the other, Mexico is going to pay for the Wall.' This has never changed. Our new deal with Mexico (and Canada), the USMCA, is so much better than the old, very costly & anti-USA NAFTA deal, that just by the money we save, MEXICO IS PAYING FOR THE WALL!" Trump tweeted Thursday morning.
Senate Democratic Leader Chuck Schumer responded: "Mr. President: If you say Mexico is going to pay for the wall (which I don't believe), then I guess we don't have to!"
That left Cornyn saying "it remains to be seen" if Trump has a broader plan or vision to resolve the border wall funding standoff and prevent a shutdown.
"I heard him allude to having the military perhaps construct some of the border barrier. It remains to be seen," he told CNN.
Senate Majority Leader Mitch McConnell claimed he was "optimistic" a resolution would be found and the government would remain open.
State of play
The big question is how House GOP leaders, in their final days in the majority, will proceed. As of Wednesday night, decisions hadn't been finalized and strategic disputes remained inside the conference.
House Majority Leader Kevin McCarthy, pressed by CNN's Manu Raju, said House Republicans have the votes to approve Trump's $5 billion in wall funding, but they have yet to schedule a vote as leadership debates the merits of doing so in the face of Senate defeat.
Less than two weeks remain before agencies including the Treasury Department, Department of Homeland Security and Justice Department could see a halt to their funding over the issue, as Congress hits a deadline for seven appropriations bills that still need to be passed. The fight remains over the Department of Homeland Security funding measure -- specifically, Trump's wall funding request.
Democrats and Republicans still aren't talking about next steps, but aides with direct knowledge tell CNN there's also an understanding it's up to Trump to counter his current $5 billion request.
That isn't expected until House Republicans decide on how they plan to proceed. But thanks to Trump and Pelosi's Oval Office showdown and the Senate math, House GOP leaders are having a difficult internal debate over something that will never become law.
Trump spoke to Mexican President Andrés Manuel López Obrador over the phone Wednesday evening, according to the White House. However, there was no mention of the two world leaders discussing the wall's payment.
"President Trump and Mexican President López Obrador spoke yesterday about the positive relations between our two countries. They discussed the need to address illegal migration from Central America to the United States by addressing the drivers of migration, such as insecurity and economic stagnation," the statement said.
López Obrador said in a news conference Thursday that "the conversation was very good, friendly, respectful."
But as the debate continues over who will pay for what, House Minority Leader Nancy Pelosi said Thursday Trump's tweet that Mexico would pay for the wall "doesn't make any sense."
She said Trump made a similar argument during their meeting at the White House on Tuesday.
The likely next speaker questioned the logic of using any potential economic benefit from the trade deal on a border wall.
"Maybe he doesn't understand how a trade agreement works, for him to say such a thing," she said. "I mean, really? Really?"
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