President Trump's ninth grandchild is the first child for son Eric and daughter-in-law Lara. (Evan Vucci/AP)

President Trump welcomed a new grandchild Tuesday, a baby boy born to Trump's son Eric Trump and daughter-in-law Lara Trump.

“Congratulations to Eric & Lara on the birth of their son, Eric “Luke” Trump this morning!” the president wrote on Twitter.

Moments after Trump's tweet, White House press secretary Sarah Huckabee Sanders also welcomed the birth from a White House lectern. The baby is Trump's ninth grandchild.

Eric Trump announced the birth earlier Tuesday via Twitter. The baby is his first child. It was not immediately clear where the baby was born. The couple live in New York, where Eric Trump is executive vice president of the Trump Organization.