Trump's economic advisers want to exempt commercial trade if he closes border

President Donald Trump has not yet made a decision about closing the southern border, the head of the National Economic Council said on Wednesday, but he said he and other top advisers had raised serious concerns about the potential economic impact and were proposing that commercial trade be allowed to continue.

“I don’t know if this is going to happen, the president will give his views today or as the days go by, but anything we can do to ameliorate the economy story we will do,” Larry Kudlow said. “It’s being looked at very, very carefully.”

Last week, the president threatened to close either parts or all of the southern border and on Wednesday morning, continued to put pressure on Congress to take legislative action to “eliminate the loopholes” at the border.

“Congress must get together and immediately eliminate the loopholes at the Border! If no action, Border, or large sections of Border, will close. This is a National Emergency!” Trump tweeted.

If the president decides to close the border, Kudlow said he has been in touch with top administration officials about how to mitigate the potentially costly damage to the economy. One suggestion Kudlow made was closing lanes of transportation for travel, but keeping freight lanes open to cut down on commercial supply-chain disruption.

“I’ve talked to various officials and DHS and others who are more knowledgeable than I, and that is possible.”

Kudlow acknowledged that both he and Kevin Hassett, Chairman of the Council of Economic Advisers, have advised the president on the economic impact of closing the border. On Tuesday, the president said that border security is more important to him than trade.

“Trading is very important. The borders are very important. But security is what is the most important," Trump said on Tuesday in the Oval Office with NATO Secretary-General Jens Stoltenberg.

"All you hear me talking about is trade, but let me just give you a little secret -- security is more important to me than trade. So we're going to have a slower border or a closed border."

A chorus of Republicans, including Senate Majority Leader Mitch McConnell, and industry leaders such as the U.S. Chamber of Commerce, have warned the president against shutting down the border.

“Closing the U.S.-Mexico border would inflict severe economic harm on American families, workers, farmers, and manufacturers across the United States,” Neil Bradley, chief policy officer of the U.S. Chamber of Commerce said in a statement on Wednesday.

“U.S. trade with Mexico exceeds $1.7 billion daily, and nearly half a million people legally cross the southern border every day as workers, students, shoppers, and tourists. Even threatening to close the border to legitimate commerce and travel creates a degree of economic uncertainty that risks compromising the very gains in growth and productivity that policies of the Trump Administration have helped achieve.”

But while Kudlow said the president is correct to be sounding the alarm about immigration, he wouldn’t agree with the president that security is more important than trade.

“I think they’re both essential,” Kudlow said when asked about the president’s comments. “I fully support him and his efforts to try to solve this border crisis and the issue of border security is not an easy thing to do ...if you could wave the magic wand, you just need immigration reform."

Both the president and White House press secretary Sarah Sanders said that Mexico has stepped up and has made serious efforts to decrease migration across the U.S. - Mexico border.

"They have started to do a significant amount more, we've seen them take a larger number of individuals and hold in Mexico that have asylum claims while they wait to be processed in the United States," Sanders said. "We've also seen them stop more people from coming across the border so that they aren't even entering into the United States.”

At a press conference on Wednesday, the president of Mexico, Andres Manuel Lopez Obrador, dodged a question about whether or not Mexico was actually increasing detentions of Central American migrants at the border but struck an optimistic tone that Trump would not actually shut down the border.

"We are acting very prudently. And we are looking for the law to be respected and we are doing very well," Lopez Obrador said. "I'm not pessimistic, I'm optimistic, I think things are going to work out."

ABC News' Kirit Radia contributed to this report.