Angola is annoyed. Angola is very annoyed. The Angolan mission in New York has had to cancel 35th anniversary celebrations after Bank of America froze and then closed all their accounts. They are currently unable to access money previously deposited to cover operational costs. Which means that this embassy is no longer able to function. It appears that Angola is one of around 20 African countries with the same problem.
It is not entirely clear why this is happening but it is possible that is has something to do with the fact that there are concerns about transparency and anti-money-laundering activities in these countries. A report states that HSBC (the Angolan mission's former bank) was pressured by the US Senate in June to stop doing business with several private Angolan banks. But that is not the same as cutting off the government.
The UN is also in New York. A country mission in New York is generally not simply one to the US, but also works with the UN . And the UN needs all of these countries to be able to operate there. Cutting off the bank accounts of any mission whose country has some banks that have dodgy banking practices may prove to be an issue. A mission cannot function without access to money from its home country.
The US Department of State have said the government doesn't control the banks but they will try to "reach out" to banks in an effort to resolve the situation. The Angolan ambassador to the US has returned home for consultations with her government. Angola is the 6th-largest supplier of imported oil to the US.