The United States expels 2 Cuban diplomats in Washington, DC

US President Donald Trump smiles during a cabinet meeting at the White House in Washington, DC, June 12, 2017. (Photo by AFP)

The United States has expelled two diplomats from the Cuban Embassy in Washington, DC, according to Department of State spokesperson Heather Nauert.

Nauert said on Wednesday the expulsions were in response to a series of attacks on a group of US diplomats in Havana with a covert sonic weapon.

"Some US government personnel who were working in our embassy in Havana, Cuba on official duty… they reported some incidents which have caused a variety of physical symptoms," Nauert stated.

"We can tell you that on May 23, the State Department took further action. We asked two officials who were accredited at the embassy of Cuba in the United States to depart the United States. Those two individuals have departed the United States,” she said.

American officials told The Associated Press that five diplomats, some along with their spouses, had been affected by the attacks in which a covert sonic weapon allegedly was used.  The FBI and Diplomatic Security Service are investigating.

Nauert said that investigators could not determine yet the real reason behind incidents but stated they take them "very seriously".

"We requested their departure as a reciprocal measure since some US personnel's assignments in Havana had to be curtailed due to these incidents," she said.

"Under the Vienna Convention, Cuba has an obligation to take measures to protect diplomats,” she added.

Former US President Barack Obama re-established diplomatic relations with Havana in 2015 and loosened some restrictions on doing business in the country during his tenure in the White House.

During last year’s presidential campaign, Donald Trump threatened to “terminate” deals that the Obama administration made with Cuba.

Now, according to source, President Trump is considering sanctions against Cuba in a bid to scale back Obama’s policy shift towards the southern neighbor.