It's all right here — but you can't see it yet.

That's what President Donald Trump told reporters Tuesday as he removed a piece of paper from his suit jacket pocket, waved it around and claimed it contained the details of his secret agreement with the Mexican government that Mexican officials have expressed confusion about.

"Right here is the agreement," Trump said. "It's very simple. It's right here. And in here is everything you want to talk about. Done. It's done. It's done."

He added: "That's the agreement that everybody says I don't have."

In showing reporters the single sheet of folded paper, Trump said he could not yet show the contents of the document because he wanted to let Mexico announce the agreement "at the right time."

"Here's the agreement. A very simple agreement," the president added. "This is one page of a very long and very good agreement for both Mexico and the United States. Without the tariffs, we would've had nothing. We had nothing two weeks ago."

"I just give you my word and I would love to do it but you will freeze action it," Trump said, pointing to the paper. "You will stop it, you will analyze it. Every single letter you'll see. But in here is the agreement."

Trump has claimed Mexico cannot yet announce the agreement because it must go through its legislature. He has promoted this apparent secret agreement in the days since it was reported that his deal to avert tariffs with Mexico did not contain much new on stemming the flow of migration toward the United States that the two nations hadn't already agreed to.

Mexico has denied the existence of any such secret agreement. On Monday, Mexican Foreign Secretary Marcelo Ebrard held up his own sheet of paper and pointed to the publicly announced details of the agreement, the Associated Press reported.

"There is no other thing beyond what I have just explained," he said.

Senior administration officials have defended the deal, disagreeing with the notion the U.S. didn't get much new.

"All of it is new," acting Homeland Security Secretary Kevin McAleenan told "Fox News Sunday."

Meanwhile, a senior administration official told NBC News that although some key elements of the Friday deal were agreed to months ago, the two sides had agreed to expand on some of the previous commitments. That included Mexico agreeing to ramp up efforts to deter migrants and expanding a program to allow migrants to remain in Mexico while their asylum cases are being processed.

Speaking in Iowa on Tuesday, former Vice President Joe Biden highlighted the piece of paper Trump was waving as evidence of his secret deal.

"I understand that he has a secret important document with Mexico," Biden said in Mount Pleasant. "And I’m sure that for a heck of a lot of Iowans being crushed by his tariffs, they would like to see that secret document."