A likely shutdown of the Department of Homeland Security has led House Speaker Mike Johnson, R-La., to cancel the official delegation of House members set to attend the Munich Security Conference, Politico reported.

Johnson has been pressuring members not to attend on their own, sources told Politico.

The Department of Homeland Security is expected to shut down Saturday after Senate Democrats blocked a short-term funding bill Thursday.

Congressional travel is typically canceled during a shutdown.

About two dozen lawmakers had planned to attend the annual conference, including Rep. Alexandria Ocasio-Cortez, D-N.Y., who was set to speak at the event.

Ocasio-Cortez was on her way to the event Thursday evening, and her office told NBC News that she was not part of the official House delegation and will attend the conference regardless.

Rep. Yassamin Ansari, D-Ariz., said she also plans to attend.

"Domestic immigration policy is foreign policy, and [President Donald] Trump's cruel detention practices shape how the world reads our values," Ansari said in a statement.

"When the U.S. dehumanizes people in detention, we undermine our human rights credibility abroad, strengthen authoritarian narratives and fuel further displacement and desperation," she added.

Lawmakers who attend cannot take military flights and would have to arrange commercial flights.

It is unknown if they will seek reimbursement from the House, Politico reported.

Rep. Joe Wilson, R-S.C., defended Johnson's stance as he lamented lawmakers having to miss the conference.

"It's a very responsible position by the speaker which matches the irresponsibility of the Senate Democrats to shut down the government," said Wilson, a senior member of the House Foreign Affairs and Armed Services committees.

"And so, the responsible act is to be ever available to end the shutdown," he added.

Sen. Lindsey Graham, R-S.C., is leading a bipartisan convoy of 11 senators to the conference.

Sen. Jeanne Shaheen, D-N.H., is leading another bipartisan delegation to the conference.