How to watch Biden's State of the Union address

President Joe Biden will deliver his State of the Union address -- his third -- on Thursday night.

But this year, the traditional annual update to Congress and the nation could have additional significance -- coming in the middle of a presidential election.

Here's what you need to know about the speech and how to watch.

When is it?

Biden will address a joint session of Congress at the Capitol on Thursday at 9 p.m.

The State of the Union is a presidential duty mandated in the Constitution, which calls for the president "from time to time to give to the Congress Information of the State of the Union."

Speaker Mike Johnson extended the formal invitation for the president to address Congress, which Biden accepted in January.

"In this moment of great challenge for our country, it is my solemn duty to extend this invitation for you to address a Joint Session of Congress on Thursday, March 7, 2024, so that you may fulfill your obligation under the U.S. Constitution to report on the state of our union," Johnson's invitation said.

How can I watch?

ABC News will air the State of the Union live at 9 p.m., ABC News Live will stream special coverage starting at 7 p.m. and ABC News Digital will have a live blog starting at 7 p.m.

You can also watch the speech live on the White House website as well as on its YouTube, X and Facebook pages.

What's at stake?

The State of the Union address can be a bit of political theater, but this year it could be more consequential as Biden aims to project confidence and connect with voters in an election year.

Presidents often use the State of the Union speech to unveil new policy proposals. In 2022, Biden used the speech to announce his "unity agenda for the nation," which included expanded health care benefits for veterans.

Earlier this week, White House press secretary Karine Jean-Pierre gave reporters a brief preview of what to expect, saying "it's going to be an important moment."

Jean-Pierre made it clear that during his State of the Union, Biden will drive home the message that his administration has and will continue to fight for lower costs for Americans.

"Our administration's action to ban hidden junk fees will save Americans more than $20 billion a year," Jean-Pierre said Tuesday. "The president will make clear in his State of the Union that he will continue fighting to lower costs for families."

While not going into detail, the White House acknowledged that Thursday's address to American voters comes at a critical moment.

"He knows how important it is for the American people to hear directly from him," Jean-Pierre said.

Biden will be taking his State of the Union message straight from Capitol Hill to the campaign trail, traveling to Pennsylvania and Georgia this weekend with two campaign remarks currently on his schedule.

Who will be there?

The State of the Union marks one of the rare times all branches of government are under the same roof. The president, members of Congress and Supreme Court justices attend.

The speaker of the House and vice president sit behind the president while he speaks. This will be the first time Speaker Johnson has sat behind the president during the address.

Invited guests also attend the event.

The White House and members of Congress typically invite guests with specific backgrounds and stories that are important to them both personally and politically -- people they want to thank, to honor or even to highlight a particular issue.

Lawmakers will be hoping to draw attention to two particular issues this year: women's rights to reproductive health care, and the ongoing conflict in Israel and Gaza.

This year we're told guests include women who have fled their home states to receive abortion care; a doctor who provided abortion care for a 10-year old; the first American person born via in vitro fertilization; Wall Street Journal reporter Evan Gershkovich's parents; families of the hostages being held in Gaza; a Palestinian doctor and grad student who lost 35 family members in the current Gaza/Israel conflict; an advocate for radiation victims; health care advocate and rapper Fat Joe, to name a few.

Johnson has also invited two Gold Star parents who lost children in the Kabul airport bombing during the chaotic U.S. withdrawal from Afghanistan in 2021.

Who is speaking for the Republican Party?

Since 1966, the opposition party has a televised response to the president's State of the Union speech. This year, freshman Alabama Sen. Katie Britt will deliver the Republican response.

Britt, the youngest female senator at 42 years old, will be a sharp contrast to Biden, the oldest sitting president in American history, Johnson said.

"She is a champion for strong families, a secure border, national defense and a vibrant economy with stable prices and opportunities for all. The American people will tune in as the youngest Republican woman ever elected to the Senate turns the page on the oldest President in history," Johnson said in a statement.

Britt is from Alabama -- the state at the center of a battle over IVF. In the wake of an Alabama Supreme Court decision calling frozen embryos "children" and calling IVF access into question, Sen. Britt called for protecting "continued access to IVF services."

Rep. Monica De La Cruz will deliver the Spanish language Republican address following the State of the Union.

ABC News' Mariam Khan and Noah Minnie contributed to this report.