The original proposal was for a sea wall about 1.7 miles long. The new proposal includes sheet-metal piling and rock armor stretching for roughly 650 yards in one spot, and for about 270 yards at another end of the dunes, according to the Trump statement. Two of the club’s holes will also be moved inland.

The new plan has yet to be officially submitted to the local government.

In a statement, Tony Lowes, director of Friends of the Irish Environment, said “the sense of relief is enormous,” adding that “the threat of Trump’s Irish wall has hung over Doonbeg like a dark cloud for more than two years.”

But he said his group would need to review the Trump Organization’s proposal after it was officially introduced before making a fuller comment.

Any new plan will be considered by the County Clare authorities, and could then be appealed to a national planning review board next year. An appeal would lead to an unusual episode in Ireland’s relations with a sitting American president, and could involve a public hearing.

The Irish wall is not to be confused with the walls Mr. Trump is building to thwart neighbors at one of his two golf courses in Scotland, where relations with locals and political leaders have been tense. Such projects are among numerous potential global conflicts of interest for the incoming president. While he has said he is turning over management of his businesses to his children, it is not clear that he will undertake the kind of divestment that would alleviate conflict concerns.

An attendee at the meeting this week said the Trump Organization had been eager to avoid further delays.

“They wanted something built in time to protect the golf course,” said Fergal Smith, a Green Party activist who works with a group called Save the Waves. “The original wall was not going to get through the planning process or was going to take a long time because there had been such a strong objection. So they had to rethink it and find a quicker solution.”