Rep. Ted Lieu (D-Calif.) endorsed Sen. Kamala Harris (D-Calif.) for president on Monday, making him the first member of Congress to back her 2020 campaign.

Lieu announced his endorsement on Twitter:

I endorse @KamalaHarris for President.



Known Kamala for many years & worked together on various issues. She embraces the future, not the past, and is the person we need to move America forward.



Watch the #HarrisTownHall tonight at 7 pm PT / 10 pm ET to learn more about Kamala. https://t.co/P4ywl9U3Op — Ted Lieu (@tedlieu) January 28, 2019

Lieu, who represents part of Los Angeles, has served in Congress since 2015. Like Harris, Lieu is an outspoken critic of President Donald Trump.

“We’re proud to have his support,” said Harris press secretary Ian Sams.

With the field of Democratic candidates still emerging, very few politicians have made public endorsements in the 2020 race. Rep. Joaquin Castro (D-Texas) endorsed his twin brother, former San Antonio Mayor Julián Castro. Harris also has the backing of Oakland Mayor Libby Schaaf.

Lieu’s endorsement came one day after Harris formally kicked off her presidential campaign with a rally in Oakland, her hometown. During the event, Harris vowed to fight “for the people” and criticized Trump for dividing the country.

“America, we are better than this,” she told the crowd of roughly 20,000 people. “People in power are trying to convince us that the villain in our American story is each other. But that is not our story. That is not who we are. That’s not our America.”

Several other presidential hopefuls, including Sen. Elizabeth Warren (D-Mass.), Rep. Tulsi Gabbard (D-Hawaii) and Sen. Kirsten Gillibrand (D-N.Y.), have also entered the race, while others, including former Vice President Joe Biden and Sen. Bernie Sanders (I-Vt.), are still considering running.

This story has been updated with a quote from Ian Sams.