UPDATE 2-Clinton has no plan for 'substantive' Iran meeting

(Adds Clinton quotes in Mexico, paragraphs 6-7)

WASHINGTON, March 26 (Reuters) - U.S. Secretary of State Hillary Clinton has no plans for a "substantive" meeting with Iranian officials at a conference on Afghanistan in the Hague next week, the State Department said on Thursday.

"No substantive meetings are planned with Iranian officials at this time," said State Department spokesman Gordon Duguid when asked if Clinton planned to have a meeting with Iranian officials on the sidelines of the conference on Tuesday.

"This conference is about reaching a regional consensus about Afghanistan. It is not a conference about U.S.-Iranian relations," he said.

But Duguid welcomed Iran's participation at the Hague conference, which Clinton proposed, and said the hope was that Iran could help in stabilizing Afghanistan.

"We do want this conference to be a regional conference, which would be incomplete without Iran," Duguid said.

During a visit to Mexico, Clinton told reporters she was not going to prejudge the results of the Hague conference but Iran had a role to play in the region "and we hope it will be a constructive role."

"We have a sort of long-held view that there are going to be difficult obstacles to engaging in the short run with the Iranians but we are going to continue to reach out," she said.

While not ready for any bilateral talks, Duguid said Clinton would deal with Iran in a multilateral setting at the meeting.