The United States has warned Americans against participating in an international aid flotilla aimed at breaking Israel's naval blockade of the Gaza Strip.

A new State Department travel warning for Israel, the West Bank and Gaza, issued Wednesday, said U.S. citizens could face arrest, prosecution and deportation by Israel if they join the flotilla.

It said the Gaza coast is “dangerous and volatile” and notes the Israeli navy has stopped previous attempts to enter Gaza by sea, resulting in deaths, injuries and arrests.

Organizers say a U.S.-flagged vessel carrying a group of Americans is among at least nine ships expected to attempt the Mediterranean voyage later this month, despite Israeli warnings.

Israel calls the flotilla a provocation and has stepped up diplomatic efforts to block it. Israel's ambassador to the United Nations, Ron Prosor, warned the international body the planned flotilla is a provocation that could have “dangerous consequences.”

He made the comments in letters, released Wednesday, to U.N. Secretary-General Ban Ki-moon and the Security Council.

In May last year Israeli commandos stormed an aid flotilla bound for Gaza, killing eight Turkish activists and one U.S. national of Turkish origin.