Washington, Jun 18 (IANS/EFE): Spain and the US signed an amended version of the 1988 bilateral defence partnership here to allow American troops permanent use of the Moron air base near the Spanish city of Seville.

The agreement signed by Secretary of State for Foreign Affairs, Ignacio Ybañez, and US Deputy Secretary of State Tony Blinken on Wednesday will allow the US military to deploy up to 2,200 soldiers and 500 civilians at the base to provide a rapid reaction force to respond to crises in Africa and the Middle East.

The US has been using the air base as a forward staging area for such efforts since early 2013.

The amended version of the pact was scheduled to be signed in late May in Madrid by US Secretary of State John Kerry, but the biking accident he suffered in Switzerland forced him to postpone his visit and the signing and ultimately send Blinken in his stead.

Blinken delivered to Ybañez a personal letter from Kerry, who is still recovering from a broken leg, directed to his Spanish counterpart, Jose Manuel Garcia-Margallo, in which he expressed his wish that he could have been present at the signing.

Ybañez said that this newly revised accord is further proof of a bilateral partnership that goes beyond the military sphere and is of great importance to both countries.

"We're very pleased to offer this cooperation, which in this case is focused on military matters, but which is much deeper and has many more elements," the Spanish secretary of state said.

Blinken also said in a brief address at the signing that "we are grateful to our allies, partners and friends... On each day that goes by, our relationship grows stronger".

The new treaty will permit the establishment of a permanent rapid reaction force with more than double the number of US troops -- all of whom presently belong to the Marines -- currently stationed at Moron.

The amendment to the cooperation accord must now be discussed and approved by the Spanish Parliament.