A fisherman from El Salvador, who washed ashore on the Marshall Islands after more than a year adrift in the Pacific Ocean, has returned home.

A frail Jose Salvador Alvarenga, 37, received a rousing welcome home as he was wheeled in before a media throng at El Salvador's international airport.

He was given a microphone to address the crowds of international media that had gathered at the airport for his arrival, but he was too weak to speak.

Mr Alvarenga told officials on the Marshall Islands that he set sail on a shark fishing trip from Mexico in late December 2012, about 6,200 miles away, but was blown out to sea.

He said he survived by drinking turtle blood and catching fish and birds with his bare hands, but he did not give further details on his experience.

Foreign Minister Jaime Miranda spoke of Mr Alvarenga's ordeal and asked for his privacy to be respected.

"It was very brief but it was a warm welcome for Jose Salvador Alvarenga, our Salvadoran brother who, as you all know, has lived through a unbelievable crossing of the Pacific, and who finally, after this difficult journey, he has returned to his homeland," said Mr Miranda.

"Jose has not only returned from a long and intense journey by sea, but also his return from the Marshall Islands has been prolonged and has required a lot of endurance.

"Due to his fragile health, it is very important for him to receive adequate medical attention and we also ask that his privacy is respected all the time."

The "castaway" is expected to be transferred to a hospital where he will be monitored by doctors.

Mr Alvarenga was found in a disoriented state on a remote coral atoll where he had been washed up in his 7.3-metre boat.

According to authorities, Mr Alvarenga, who has been a fisherman for 15 years, said he set sail with another fisherman, aged 15 to 18, but the teenager died a month into their ordeal.