President Donald Trump announced Friday an agreement with Mexico on tariffs.

"I am pleased to inform you that The United States of America has reached a signed agreement with Mexico. The Tariffs scheduled to be implemented by the U.S. on Monday, against Mexico, are hereby indefinitely suspended," officials said.

In order for the 5 percent tariffs to have gone into effect June 10, Trump would have had to sign an executive order directing them to do so on Friday, a White House official confirmed to NBC News. The order would not be binding, the official noted, meaning Trump could still pull the plug on the tariffs over the weekend if the two sides were to strike a deal.

Asked if it was possible Trump would do so, Kevin Hassett, the outgoing chair of the Council of Economic Advisers, told NBC News the president “always has every option on the table.”

Mexican President Andrés Manuel López Obrador told reporters in Mexico City that "it's a good sign that talks have not broken down."

"There is dialogue and an agreement can be reached. I'm optimistic we can achieve that," Obrador said.

Trump announced that he would impose the tariff last week, and that it would "gradually increase" until "Mexico substantially stops the illegal inflow of aliens coming through its territory."

The two sides met for a third straight day on Friday. Administration officials say there has been “significant progress,” but stressed that Trump will have the final say.

A White House official told NBC News after negotiations Thursday that Mexico seemed willing to entertain a number of proposals that the White House had put on the table Wednesday.

Those proposals include putting 6,000 Mexican national guards at the border region with Guatemala, and the possibility of a "safe third country" designation. That would include a provision requiring Central Americans to seek refuge in the first foreign country they enter.

The Washington Post reported that such a plan would mean the U.S. would deport Guatemalan asylum-seekers to Mexico, and Honduran and Salvadoran applicants to Guatemala.

Mexico had initially said a "safe third country" designation would be a red line.

The White House said Mexican officials were also considering a proposal for "Migration Protection Protocols," which would require migrants seeking to come into the United States to stay in Mexico until their cases are processed.

According to a White House official, negotiations were now mainly being conducted between lawyers for both countries, including White House counsel Pat Cipollone. That was viewed as a sign the talks were pretty far along, but the source said Thursday it was "premature" to say there's a deal in place.

Marc Short, chief of staff for Vice President Mike Pence, told Fox News that Cipollone was going "to try to hammer out some more details."

Short told reporters outside the White House that Mexico's first proposals on Wednesday had been "insufficient," but that the administration had been encouraged by how talks have proceeded since then.

"The legal teams are talking today, and we’ll see how that progresses, but it’s clear that there’s still a long way to go," Short said.

The proposed tariffs have been opposed by Democrats and several Senate Republicans, who've warned they could have a negative impact on the U.S. economy. Trump has said Republicans would be "foolish" to try to block his plans.