"We have seen the tweets that include the letter, we are verifying the authenticity and the response will be considered," Dujarric said.
The official further noted that UN Secretary-General Antonio Guterres had not received any official information concerning changes in the government of Venezuela.
"We have not received any information there have been any changes in the government of the country," Dujarric told reporters.
The spokesman explained that if a UN member-state undergoes a change in its government, a permanent diplomatic mission to the organization has to report about the change.
The situation in Venezuela escalated on January 22 when the opposition-controlled National Assembly declared President Nicolas Maduro had usurper power. The next day, Guaido proclaimed himself Venezuela's interim president.
Maduro called Guaido a puppet of the United States and accused Washington of attempting to organize a coup d’etat in Venezuela. Maduro also announced his decision to sever diplomatic ties with the United States.