945. Does Directive 1 under E.O. 14038 prohibit U.S. persons from engaging in all activities with the Ministry of Finance of the Republic of Belarus or the Development Bank of the Republic of Belarus?

No.  Directive 1 under E.O. 14038 prohibits U.S. persons from engaging in only certain activities with the Ministry of Finance of the Republic of Belarus or the Development Bank of the Republic of Belarus, as explained in FAQ 940. 

All other activities with the Ministry of Finance of the Republic of Belarus or the Development Bank of the Republic of Belarus, or involving their property or interests in property, are permitted, provided such activities are not otherwise prohibited pursuant to E.O. 14038, any Executive order issued pursuant to the national emergency declared in E.O. 13405, or any other sanctions program implemented by the Office of Foreign Assets Control.