In the same hearing, Senator Chris Coons said that around 1,100 former Afghan colleagues, including 400 children and 150 family members of US service personnel, remain stranded in Qatar.
He warned that these individuals could be sent back to Afghanistan or transferred to countries such as the Democratic Republic of Congo, which is currently grappling with the spread of the Ebola virus.
The Democratic senator called on the US Secretary of State to work with Congress to bring these individuals, particularly the family members of US service personnel, to the United States.
Rubio, however, replied: "We're obviously operating right now under a directive that prohibits the entry of Afghans into the United States." He explained that the directive followed last year's attack on members of the National Guard.
Rubio said the United States had been "engaging every single day" with several countries to accept some of these Afghans, and that several countries had indicated their willingness to take in some of those waiting in limbo.
He told Senator Coons that the administration would continue to work to find suitable locations to resettle these individuals.
Following the shooting by an Afghan asylum seeker of US National Guard personnel in Washington last November, the Trump administration tightened restrictions on the admission and travel of Afghans to America. Under a directive, Trump banned the entry into the United States of citizens of 12 countries, including Afghanistan.
American media have reported that the Trump administration is examining a plan to transfer several of the Afghan asylum seekers currently at the Al Sayliyah camp in Qatar to the Democratic Republic of Congo.
The plan has drawn widespread criticism. More than 600 former US civilian and military officials, in an open letter, have called on the Secretary of State to abandon the proposal to transfer Afghan asylum seekers to Congo.
Meanwhile, Chris Coons criticised America's current restrictive policies on asylum seekers, saying that those who entered the United States under asylum programmes had been among those who passed the most stringent security vetting and had played an important role in the country's development.
He added that asylum seekers who had fled repression and instability in countries such as Cuba, Venezuela, Vietnam, and Afghanistan had, over recent decades, made a significant contribution to the progress of the United States.