BRUSSELS, April 9 (Reuters) - The ceasefire agreement between the United States and Iran should extend to Lebanon, EU's top diplomat Kaja Kallas said on Thursday, adding that Iran-backed Lebanese group Hezbollah must disarm.

"Israeli actions are putting the U.S.-Iran ceasefire under severe strain. The Iran truce should extend to Lebanon," Kallas said in a post on X.

"Israeli strikes killed hundreds last night, making it hard to argue that such heavy-handed actions fall within self-defence," she also said.

(Reporting by Inti Landauro, Writing by Charlotte Van Campenhout, Editing by)