Washington (CNN) The House Judiciary Committee is requesting information about reports that President Donald Trump told Customs and Border Protection Commissioner Kevin McAleenan he would grant a pardon if McAleenan was sent to jail for having border agents block asylum seekers from entering the US.

"These allegations, if true, would represent a grave breach of the duties of the President," the letter, directed to now Acting Homeland Security Secretary McAleenan, reads.

The request comes on the heels of a letter from three House committee chairmen Monday requesting documents related to Trump's proposal to release immigrants into so-called sanctuary cities.

Over recent weeks, the President has continued to criticize the nation's immigration laws, suggested a border closure and tariffs against auto imports and forced the resignation of Homeland Security Secretary Kirstjen Nielsen.

CNN's Jake Tapper reported last week about the exchange between Trump and McAleenan. Trump reportedly made the comment during a visit to the border at Calexico, California, earlier this month.

Two officials briefed on the exchange say the President told McAleenan, since named the acting secretary of the Department of Homeland Security, that he "would pardon him if he ever went to jail for denying US entry to migrants," as one of the officials paraphrased.

In its letter, the committee, led by Democratic Rep. Jerry Nadler, requests a list of DHS employees present for McAleenan's meeting with Trump in Calexico; a list of employees who attended Trump's meeting with Border Patrol agents around the same time; and documents and communications related to Nielsen's meeting with Trump "on or about March 21, 2019 to discuss reinstating the zero-tolerance policy and closing the US-Mexico border at El Paso, Texas."

The deadline is April 30.

"The reported discussion between you, President Trump, and other Department personnel follows a troubling pattern of conduct that has emerged over the past two years that appears to demonstrate that President Trump views the pardon power as a political tool, or even worse, as an expedient mechanism for circumventing the law or avoiding the consequences of his own conduct," the letter from the Judiciary panel reads.

Asked about the pardon comments, the White House referred CNN to the Department of Homeland Security, where a spokesman told CNN, "At no time has the President indicated, asked, directed or pressured the Acting Secretary to do anything illegal. Nor would the acting secretary take actions that are not in accordance with our responsibility to enforce the law."

Trump denied reports he offered pardons in a tweet late Friday night.

The exchange came amid threats by the President to close the border in response to a steep uptick of migrants at the border. In March, there were approximately 92,000 arrests of undocumented migrants for illegal entry on the southern border, up from 37,390 last March, according to CBP.

Behind the scenes, two sources told CNN, the President told border agents to not let migrants in. "Tell them we don't have the capacity," he said. "If judges give you trouble, say, 'Sorry, judge, I can't do it. We don't have the room.'" The House Judiciary Committee letter cites the exchange in its letter to McAleenan.

After the President left the room, agents sought further advice from their leaders, who told them they were not giving them that direction and if they did what the President said they would take on personal liability. You have to follow the law, they were told.