No handshakes, selfies or fist bumps when Pope Francis enters the House chamber for his historic speech to Congress.

That's the message from House and Senate leaders, who in a letter asked lawmakers to refrain "from handshakes and conversations along and down the center aisle during the announced arrivals of the Senate, dean of the Diplomatic Corps, U.S. Supreme Court, president's Cabinet and Pope Francis."

The pontiff will be on a tight schedule Thursday, and congressional leaders want to avoid anything that could slow him down, such as members of Congress shaking hands with the chief of one of the departments or greeting a Supreme Court justice or even the pontiff himself.

The pope is scheduled to arrive at the Capitol shortly after 9 a.m. EDT, meet with House Speaker John Boehner, then address a joint meeting of Congress in the House chamber at 10 a.m. Vice President Joe Biden, diplomats, justices and Cabinet members are expected in a jam-packed chamber.

House members and senators each were allocated one ticket to distribute for seats in the House gallery to view the speech.

The speech also will be telecast on giant screens on the West Lawn of the Capitol, where up to 50,000 people with tickets are expected to view it.

House members were given 50 standing-room tickets for the West Lawn and senators were given 200. Lawmakers also were each allocated one ticket to distribute for viewing from the lower west terrace of the Capitol.

After his speech to Congress, the pope will appear on the Capitol balcony facing the National Mall to address the crowds.

In total, Francis is to be in the Capitol for 90 minutes.