"We have reminded the Cuban government on various occasions that, under the Vienna Convention, this type of treatment of diplomatic personnel is unacceptable", the State Department official said at the time.
It comes a day after the United States said its diplomats in Havana were experiencing unusual physical symptoms.
United States officials, speaking to the agency anonymously, said investigations had determined devices had been deployed either inside or outside diplomats' homes.
The US says two Cuban diplomats have been expelled in response to "incidents" in Cuba, but the details remain mysterious.
In fall 2016, the United States diplomats reportedly began suffering unexplained losses of hearing.
In 2015, US and Cuban relations took a major turn, as America reopened the doors to its embassy in Havana. As a result, the USA on May 23 asked two Cuban officials in Washington to leave the country and they have done so.
Nauert confirmed that the Cubans left Washington on May 23.
Cuba denies the allegation, but the USA has removed two Cuban diplomats from Washington DC in retaliation. Along with probing possible Cuban responsibility, investigators are also exploring the possibility that the attack was carried out by a third country, like Russian Federation, operating without the Cuban government's knowledge.
The U.S. first learned of the issues at the embassy in late 2016, she said.
Nauert said that the two Cuban diplomats were "asked to leave" in May, but she declined to characterize their departure as reciprocity for the incidents.
"We have some Americans who choose to come home as a result of that", said Nauert. "We're taking this incident very seriously, and it's under investigation right now". CNNquotes an unnamed official who stated, "We have worked with the Cubans to try and find out what is going on".
President Trump announced a couple of months ago he was rolling back numerous advances with Cuba that Obama had overseen.
The Cuban foreign ministry said it would not allow its territory to be used for any action against accredited diplomatic agents or their families.
Rick Porcello threw an immaculate inning against the Rays
However, Wood and the Dodgers trailed 2-1 in the seventh until Joc Pederson hit an RBI double and scored on Yasiel Puig's single. Houston's recent struggles continued as the AL West leaders absorbed a second straight loss to the last-place White Sox, 7-1.
Zuma wins 8th motion of no confidence - #StateCapture
The motion was brought by the Democratic Alliance following the release of the Public Protector's State of Capture report. "The Speaker, Baleka Mbete , will become acting president and have 30 days to elect a new president", he explained.