"In line with the ceasefire in Lebanon, the passage for all commercial vessels through Strait of Hormuz is declared completely open for the remaining period of ceasefire, on the coordinated route as already announced by Ports and Maritime Organisation of the Islamic Rep. of Iran," Foreign Minister Abbas Araghchi wrote on X.
The news drove down oil prices, with Brent crude tumbling below $90 a barrel for the first time since early March.
US President Donald Trump thanked Iran for opening the Strait of Hormuz.
"IRAN HAS JUST ANNOUNCED THAT THE STRAIT OF IRAN IS FULLY OPEN AND READY FOR FULL PASSAGE. THANK YOU!" he wrote on Truth Social.
Trump added that the US will continue its naval blockade of the strait until a US-Iran deal is fully completed.
"The naval blockade will remain fully in force as it applies only to Iran until our transaction with Iran is 100% complete. This process should move very quickly, since most of the points have already been negotiated," he wrote.
On April 11, the US and Iran held several rounds of talks in Islamabad. Officials in both Tehran and Washington said no deal was reached on a long-term settlement due to multiple disagreements. The Associated Press reported that a new round of negotiations could take place on April 16.