WASHINGTON — U.S. and Mexican officials met Thursday for a second day of negotiations over President Donald Trump’s threatened tariffs against Mexico, appearing to move closer toward a deal as the president's Monday deadline neared.

The meeting, which is expected to resume later Thursday evening, came a day after officials began talks to prevent the tariffs from taking effect on Monday.

A White House official told NBC News Thursday afternoon that "significant progress is being made on the talks with Mexico" and that Mexico had appeared to be more willing to entertain a number of proposals that the White House had put on the table during Wednesday's meeting.

Among the proposals that Mexico appeared to be considering was the possibility of a "safe third country" designation, which would require Central Americans to seek refuge in the first foreign country they enter. According to the White House official, Mexico also appeared to be more open to the "Migration Protection Protocols," which would require migrants to stay in Mexico until their cases are processed.

However, the White House official cautioned that details still needed to be worked out and that even then, it was not clear if Trump would accept terms once they are reached.

“Position has not changed, and we are still moving forward with tariffs at this time,” White House press secretary Sarah Sanders said Thursday.

Vice President Mike Pence sounded a similar note. "There's been some movement on their part that’s been encouraging, but at the end of the day, we'll as those discussions wrap up today, we’ll evaluate those proposals," he told reporters Thursday afternoon, following an event in Harrisburg, Pennsylvania. "We’ll present them to the president, but ultimately President Trump will make the decision whether or not the actions Mexico is prepared to take are sufficient for us to consider changing course. But at this point, the tariffs are going to be imposed on Monday."

The meeting Thursday at the State Department was attended by several staff level officials from the White House, the Department of Homeland Security, the State Department, as well as Mexican officials. Trump and Vice President Mike Pence were both traveling and not in attendance.

Speaking to reporters in Shannon, Ireland, before departing Thursday morning for Normandy, France, President Donald Trump said “a lot of progress was made” Wednesday, but Mexico had to “step up to the plate” to curb illegal immigration to the U.S.

“We'll see what happens,” Trump said. “But something pretty dramatic could happen. We've told Mexico the tariffs go on. And I mean it, too. And I'm very happy with it. And lot of people, senators included, they have no idea what they're talking about when it comes to tariffs. They have no — absolutely no idea.”

In an interview with Fox News later in the morning, Trump said Republicans in Congress, who have expressed concerns over the tariffs, "should love what I'm doing."

"When you're the piggy bank that everybody steals and robs from, and they deceive you, and they've — like they've been doing for 25 years — tariffs are a beautiful thing," Trump said. "It's a beautiful word if you know how to use them properly."

During the meeting on Wednesday, which lasted about an hour and a half, the Mexican delegation had offered what the White House said it viewed as a “good faith,” if “minimalist,” approach to solving the “crisis” at the border, a senior administration official who attended the meeting said.

Trump threatened last week to impose a 5 percent tariff on Mexican imports beginning Monday, June 10, with the tariffs climbing to as high as 25 percent over time.

Senate Republicans voiced strong opposition to the policy this week. Senate Majority Leader Mitch McConnell, R-Ky., on Wednesday asked White House officials to urge Trump to delay the tariffs until he is back in the country and able to meet with party members to hear their concerns and share his views directly on such a major policy change, according to two Republican officials familiar with the exchange.

House Speaker Nancy Pelosi, D-Calif., said Wednesday that Trump is treating Mexico like an “enemy” and suggested he is overstepping his presidential authority.

“We haven’t seen anything yet except a tweet — a tweet and then this statement of the authority under which they would do this," Pelosi said. "But we haven’t seen anything that we would be overruling and then going to the next step."

“I think that this is dangerous territory," she said. "This is not a way to treat a friend. It’s not a way to deal with immigration. It’s not a way to deal — to meet the humanitarian needs at the border.”