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ANKARA, May 26 (Reuters) - Iran's Supreme Leader Ayatollah Ali Khamenei called for vigilance against what he called a "soft war" mounted by the West and aimed at weakening the clerical establishment, state television reported on Thursday.

"Our officials and all parts of the establishment should be vigilant about the West's continued soft war against Iran ... the enemies want to weaken the system from inside," Khamenei said.

In a meeting with members of the Assembly of Experts, with authority to appoint and dismiss the supreme Leader, Khamenei told Iranian officials:

"By impairing centres of powers in Iran, it will be easy to harm the establishment from inside," Khamenei told members of the Assembly of Experts.

The 88-member assembly, consisting mostly of elderly clerics, is expected to choose any successor to Khamenei, who has the final say on all state matters.

"The only way to materialise the (1979 Islamic) revolution's goals is national unity and not to obey the enemy," Khameni said.

(Writing by Parisa Hafezi; Editing by Ralph Boulton) ((parisa.hafezi@thomsonreuters.com; +90 532 176 3452; Reuters Messaging: parisa.hafezi@thomsonreuters.com))