Can I claim my child as dependent when he just obtained the CRBA?

My child was born on 12/31/2019 abroad.

He is my biological son.

My wife is a non-US resident. She is Vietnamese nationality.

I got an interview schedule with the US consular in Vietnam and they granted my son the CRBA (Consular report of birth abroad) certificate in March 2020.

The complication comes in when I need to file my tax for 2019. Can I claim him as my dependent? I provide more than half of his support.

According to the citizenship rule, he should be a US citizen at birth since I am a US citizen who have been physically in the US for more than 5 years.

 

"A child born abroad to one U.S. citizen parent and one alien parent acquires U.S. citizenship at birth under Section 301(g) of the INA provided the U.S. citizen parent was physically present in the United States or one of its outlying possessions for the time period required by the law applicable at the time of the child's birth."

 

However, he didn't get his citizenship certificate until March/2020. So I am confused can I still claim him as my dependent since he should have been a US citizen at birth, which was 12/31/2019.

 

Thanks in advance