Italy said late on Monday it was ready to take all the migrants to a Spanish port, since it has refused the docking request from Open Arms, a ship with 107 migrants aboard and has been stranded at sea for 18 days. It's not immediately clear if the offer was conditional.

For more than two weeks, the migrants have been left floating off the Italian coast, caught between a tug of war between Italy's far-right interior minister Matteo Salvini's tough line on immigration and the EU's initial reluctance to find a solution.

Salvini had allowed 27 minors to leave the boat on Saturday, saying he was only doing so on the prime minister's instructions, as sanitary and hygienic conditions aboard were very poor, and the medical and psychological condition of people aboard has reached a breaking point when doctors visited the ship last week.

The Open Arms ship, run by a Spanish charity of the same name, saying disembarking in Mallorca would add another three days to what has been a trying situation.

"If an agreement has indeed been reached, it's essential for Italy and Spain to take responsibility for ensuring, by providing the necessary means that these people finally disembark at a safe harbor," the organization said in a statement.

It also said the migrants aboard are distressed and in no condition to sail to Spain in such cramped conditions on board, and the ship's resources were also exhausted, suggesting that Italy's Coast Guard should take the migrants to Spain.

"We have exhausted physically, morally and technically the few resources that this organization has in this moment,” Open Arms' director and founder, Oscar Camps, told Reuters on Monday.

Camps said the Italian Coast Guard had offered to provide an escort and to carry some of the migrants to end the standoff, which he says is at crisis point, although the offer is obviously insufficient for the ship. Camps said Open Arms wanted the Coast Guard to take all the migrants to Spain.

"(I say) that they not only carry a part but carry them all and that they carry them in a safe and dignified way," he said.

Spain and five other EU countries last week offered to take the migrants, but until the ship disembarks the distribution plan could not be set in motion.

"European states are asking a small NGO like ours to deal with three days of navigation, in adverse weather conditions, with 107 exhausted people on board,' the Guardian quoted Riccardo Gatti, the president of Open Arms as saying, "This is completely incomprehensible."

If a solution is not found, Open Arms has not ruled out the option of defying Italy's ban and attempting to dock. The ship has been sitting for days off Lampedusa, watched by an Italian patrol boat stationed nearby. Asked if the ship would try and enter the port without permission, Open Arms' head of mission in Lampedusa, Riccardo Gatti, replied: "Yes it is an option."

Under new laws introduced by Salvini, ships that enter Italian waters without authorization face a fine of up to 1.11 million U.S. dollars. The ships can also be seized. 

Spain's acting defense minister, Margarita Robles, said Salvini was putting human lives at risk for "absolutely electoral reasons," adding: "What Salvini is doing regarding the Open Arms is a shame for all humanity."

(With input from agencies)