MAJURO, Marshall Islands (AFP) - A Mexican castaway who says he drifted for months across the Pacific Ocean before washing up on a remote Marshall Islands atoll was on his way to the capital on Sunday, hoping to begin his long journey home.

The castaway, who has given his name as Jose Ivan, was picked up from isolated Ebon Atoll on Sunday morning by a Marshall Islands sea patrol ship on course for the islands' capital Majuro, where he will undergo medical examinations.

"I want to get back to Mexico," Mr Ivan told interpreter Magui Vaca in his first interview through a Spanish-speaking interpreter since drifting into the atoll on a 24-foot fibreglass boat.

"I feel bad," he told Vaca of his physical and mental state. "I am so far away. I don't know where I am or what happened."

Mr Ivan said that he had left Mexico on December 24, 2012, to go shark fishing, putting his time at sea at 13 months, not the 16 months previously reported.

No details have yet emerged as to why he began drifting, or what happened to a companion he said had died a few months ago.

Ms Vaca said Mr Ivan was disorientated and didn't know what had happened during his many months at sea.

"He feels a little desperate and he wants to get back to Mexico, but he doesn't know how," she said.

When Ebon islanders discovered Mr Ivan on their remote atoll on Thursday they said he was wearing only ragged underwear, sporting a long beard and unable to walk without assistance.

The castaway indicated that he survived by eating turtles, birds and fish and drinking turtle blood when there was no rain.

"It's been difficult trying to communicate with him," said Ebon Mayor Ione deBrum, adding that Ivan had interacted with her through drawings.

Ms Vaca was on a yacht in Majuro Atoll - around 200 miles (320 kilometres) north of Ebon - when she spoke to Mr Ivan via radio, moments before the Mexican was ushered onto the sea patrol vessel for the estimated 18-hour trip.

Ministry of Foreign Affairs officials said Friday that as soon as Mr Ivan arrived in Majuro and more detailed information was available, they would initiate official communication with Mexican government officials for his repatriation.

The Marshall Islands National Telecommunications Authority (NTA) worked with Mieco Beach Yacht Club officials to organise the conversation between Mr Ivan and Ms Vaca, which may have been the first time in many months that the castaway has had a conversation he could understand.

But Sunday's short interview proved difficult as the radio transmission was marred by static and it was difficult to hear.

The single phone line to Ebon - population 700 - went out of service Saturday, leaving radio the only option for communication. There is no Internet service on the remote atoll.