Foreign Minister Vijitha Herath held a telephone conversation with Iranian Foreign Minister Abbas Araghchi on Wednesday, during which Araghchi thanked the Sri Lankan government for its role in the IRIS Dena rescue operation and described the U.S. attack on the Iranian naval vessel as an “unprecedented war crime.”

According to a communique issued by the Iranian Embassy in Sri Lanka, Araghchi expressed appreciation for Sri Lanka’s efforts in rescuing the IRIS Dena sailors and assisting in the repatriation of the bodies of crew members and other Iranian naval personnel.

Outlining what he called crimes committed by the United States and Israel against Iran, Araghchi said the strike on the IRIS Dena constituted “a grave violation of the fundamental rules of international humanitarian law and the 1949 Geneva Conventions.” He said the Iranian nation “will never forget this crime” and would “employ all legal and political means to hold the perpetrators and those responsible accountable.”

The two ministers also discussed bilateral relations and regional developments.

The IRIS Dena, an Iranian naval vessel, sank in waters off Sri Lanka earlier in the U.S.-Iran conflict. Sri Lanka assisted in the evacuation of Iranian sailors and the repatriation of remains — a humanitarian role that has become a central diplomatic thread between the two countries amid the wider Middle East war.

The call comes the same week Iranian state TV questioned the April 8 ceasefire framework and Iran’s IRGC seized two container ships in the Strait of Hormuz. Earlier in the day, Reuters reported that the U.S. Navy had intercepted three Iranian-flagged oil tankers in Asian waters, including positions near Sri Lanka, India and Malaysia.