The EU announced on Monday that European nations are ready to help Washington and take detainees on a case-by-case basis.
The US government has faced opposition to releasing them in the US.
Amado met Daniel Fried, the US assistant secretary of state for European affairs in charge of resettling negotiations, on Friday.
He said the status of the detainees to be resettled in the Iberian country would be defined by the interior ministry probably next week.
Fried's job is to find host countries for the more than 200 detainees that Washington chose not to prosecute.
Guantanamo Bay, opened under George Bush, the former US president, after the September 11, 2001, attacks on the US, attracted international criticism for holding prisoners indefinitely, many without charge.
Barack Obama, the US president, ordered the Guantanamo facility to be closed by January 2010 and the inmates either face trial or be released.