The British sailors and marines after meeting with President Mahmoud Ahmadinejad of Iran in Tehran on Wednesday.(AP)

LONDON: President Mahmoud Ahmadinejad of Iran said Wednesday that the country had "pardoned" and would release the 15 British sailors and marines who have been held there for nearly two weeks.

The remarks appeared to bring a swift resolution to a crisis that began on March 23, when Iranian coast guards seized the 15 Britons in the northern Persian Gulf, saying they had trespassed on Iranian territorial waters.

Speaking at a news conference in Tehran, Ahmadinejad said that the captives would be taken to Tehran airport immediately after he finished his remarks. "They are free after this meeting, and can go back to their families," he said.

He also went out of his way to praise the coast guards responsible for seizing the Britons, interrupting his remarks to pin a medal on the chest of the coast guard commander.

"On behalf of the great Iranian people, I want to thank the Iranian Coast Guard who courageously defended and captured those who violated their territorial waters," he said.

He also criticized Britain for its involvement in the war in Iraq. "We are sorry that British troops remain in Iraq and their sailors and being arrested in Iran," the president said.

Ahmadinejad said that the captured Britons had all confessed to trespassing in Iranian waters and that Iran had "every right" to put them on trial, but had decided not to. "I want to give them as a present to the British people, to see that they are free," he said.

Afterward, he greeted the captives one by one and shook their hands.

The Iranian president said the decision to release the captured sailors and marines was not part of a swap for Iranian prisoners held by the United States in Iraq.

"We approached the subject on a humanitarian basis," he said. "It was a unilateral decision on our end."

He also said the British government sent a letter to the Iranian foreign ministry that "said that this will not happen again." But he said that the decision to release the naval personnel "was not related to that letter. When we think of Islamic kindness, we are not expecting anything in return."

In London, the British government said it welcomed the Iranian president's remarks, but that no logistics had yet been worked out for the release of the sailors and marines.

"We are now establishing exactly what that means in terms of the method and timing of their release," a Downing Street spokeswoman said.

In a ceremony after the news conference, Ahmadinejad was shown on live television greeting the British captives, who were wearing suit jackets. The president said the release was being made on the occasion of the "birthday of the great Prophet of Islam," in the words of the translator.

Ahmadinejad wished them success.

"Thank you very much," said one.

"We are very grateful for your forgiveness" said another. "We would like to thank yourself and the Iranian people."

Another said: "I am fine thank you," to the president. "Your people have been very kind to us and I appreciate that very much."