Washington: The United States is 'watching carefully' two Iranian warships that entered the Mediterranean Sea on Tuesday, officials said.
It was Iran's first passage through the Suez Canal since its 1979 Islamic revolution, and comes at a time of widespread unrest roiling the Middle East. Israel has called Tehran's move a 'hostile' act.
"We continue to monitor the movements of these ships and their actions," State Department spokesman Philip Crowley said. "We will be watching carefully to see where these ships go and the implications of that."
Crowley said the decision authorizing passage through the Suez Canal rests with Egypt - where mass protests forced the resignation of longtime president Hosni Mubarak on February 11.
"We have concerns about Iran's behavior in the region," he said.
The Kharg, a supply ship, and the Alvand patrol frigate were bound for Syria in what Tehran has described as a routine visit.
In response, Israel put its navy on alert. Israel considers Iran, which opposes the Jewish state and supports Hezbollah and Hamas, a serious threat.
The Suez Canal Authority said last week that ships of any nationality can pass through 'as long as the country is not in a state of war with Egypt'.