It should be ‘has encountered’. Due to and because of are both ok.

1. The United States has encountered a severe financial crisis due to the pandemic. 2. The United States is in the midst of a severe financial crisis due to the pandemic.

"because of" is better. "due to" is appropriately used for checked-out library books. Ref: Strunk & White

I think you’re asking if “because” or “due to” is best. Either is fine. They both are correct. However, the verb tense is not the best. Encounters is limited in time, whereas an economic crisis is ongoing. Example, an airplane encounters turbulence (the turbulence only last a minute or two and them the skies are calm). So in your example, I would use the present progressive to show that it’s ongoing. The US is encountering The US is confronting The US is dealing with The US is coping with and economic crisis

Just to comment on this . . . the others are right about the tense. You would only use this tense if you were writing it as it was happening, i.e. a couple of years ago.