DUBAI, United Arab Emirates — An Iranian-flagged oil tanker pursued by the U.S. amid heightened tensions between Tehran and Washington changed its listed destination to a port in Turkey on Saturday after Greece said it wouldn’t risk its relations with America by aiding it. The crew of the Adrian Darya 1, formerly known as the Grace 1, updated its destination in its Automatic Identification System to Mersin, Turkey, a port city in the country’s south and home to an oil terminal. However, mariners can input any destination into the AIS, so Turkey may not be its true destination. Mersin is about 125 miles northwest of a refinery in Baniyas, Syria, where authorities alleged the Adrian Darya had been heading before being seized off Gibraltar in early July. Iranian state media and officials did not immediately acknowledge the new reported destination of the Adrian Darya, which carries 2.1 million barrels of Iranian crude oil worth some $130 million. Nor was there any immediate reaction from Turkey, whose President Recep Tayyip Erdogan deals directly with Tehran and Russia over Syria’s long war. The ship-tracking website MarineTraffic.com showed the Adrian Darya’s position as just south of Sicily in the Mediterranean Sea. At current speeds, it estimated the Adrian Darya would reach Mersin in about a week. The Adrian Darya’s detention and later release by Gibraltar have added fuel to the growing tensions between Washington and Tehran, after President Trump unilaterally withdrew America from Iran’s 2015 nuclear deal with world powers over a year ago over concerns about Iran’s ballistic missile program and regional influence. In the time since, Iran lost billions of dollars in business deals allowed by the deal, as the U.S. re-imposed and created sanctions largely blocking Tehran from selling crude oil aboard,...