The argument centered around a recent surge in border crossings. President Trump, who tweeted a threat to shut down the southern border on Thursday morning, took national security adviser John Bolton's side of the issue, CNN reports.
"I must, in the strongest of terms, ask Mexico to stop this onslaught - and if unable to do so I will call up the U.S. Military and CLOSE OUR SOUTHERN BORDER!..," Trump said in a tweetstorm. "The assault on our country at our Southern Border, including the Criminal elements and DRUGS pouring in, is far more important to me, as President, than Trade or the USMCA. Hopefully Mexico will stop this onslaught at their Northern Border. All Democrats fault for weak laws!"
Bloomberg reports the shouting match was so intense, White House aides wondered if one of the two men would resign just 19 days before the midterm elections. Kelly and Bolton have reportedly had their disagreement for weeks.
The White House declined to comment on the incident.
The Washington Post reports the number of migrant families crossing the border has reached record levels in the three months since family separations ended, according to data from the Department of Homeland Security.