By Steve Holland, Jana Choukeir and Humeyra Pamuk
WASHINGTON/DUBAI/ZURICH, June 19 (Reuters) - Israel and Hezbollah agreed to a ceasefire in Lebanon on Friday, a U.S. official said, after an escalation in fighting there jeopardised the chances of an interim agreement on ending the war in Iran turning into a lasting Middle East peace deal.
U.S.-Iran talks in Switzerland planned for Friday were cancelled as fighting flared in Lebanon, creating new uncertainty about the timing of negotiations vital to ensure the reopening of the Strait of Hormuz to global shipping.
The senior U.S. official said shortly before 4 p.m. Lebanon time (1300 GMT) that a ceasefire would come into effect then.
"We understand that after the exchange of fire earlier today, Israel and Hezbollah are now in a ceasefire," the official said on background, saying that negotiators for the U.S. and Qataris worked out the agreement with help from Iran.
The flareup in Lebanon, in which 18 people were killed in airstrikes and four Israeli soldiers were killed by Hezbollah militants, could weigh heavily on negotiations because ending fighting there is a condition for the broader U.S.-Iran accord.
A senior Hezbollah lawmaker said Iran had told the group that talks with the United States could not continue without a comprehensive ceasefire.
Iran's foreign ministry spokesperson did not mention the talks but said the United States bore direct responsibility for Israeli attacks on Lebanon and that Tehran would take all necessary measures to protect its interests.
(Reporting by Reuters bureaus, Writing by Clarence Fernandez and Timothy Heritage; Editing by Raju Gopalakrishnan and Philippa Fletcher)
