"To safeguard our security and bolster our global influence, Guantanamo should be closed as soon as possible," Lehnert said.
US President Donald Trump announced during his State of the Union address on Tuesday night that he signed an executive order to keep the detention center at Guantanamo Bay, Cuba open.
Lehnert noted the move would further fuel propaganda by enemies of the United States and serve as a distraction to US allies while undermining US national interests.
In the wake of the 9/11 attacks, Lehnert deployed to Guantanamo Bay in January 2002 with the mission to construct and operate detention facilities for detainees belonging to the radical Taliban movement and the Al-Qaeda terrorist group (banned in Russia).
Meanwhile, US Senator Duane Feinstein said in a press release on Wednesday that Donald Trump was wrong to announce he was going to keep operating the Guantanamo Bay detention facility in Cuba despite a $5 billion cost so far.
"I strongly disagree with President Trump’s decision to keep Guantanamo Bay prison open," Feinstein said. "With a cost that has now topped $5 billion, keeping Guantanamo open is a drain on taxpayers and a recruiting tool for terrorists."
According to media reports, detainees in Guantanamo Bay have been held for indefinte periods without charge or trial, prompting criticism from human rights groups. The detention facility also gained worldwide notority after the emergence of evidence of widespread torture and abuse of inmates.
Former US President Barack Obama promised to close the detention facility but failed to fulfill his pledge. Trump has vowed to keep it open and bring in more captured terrorists.