Sri Lanka, April 13 -- Iran's Islamic Revolutionary Guard Corps (IRGC) warned today that "no port in the Persian Gulf and the Sea of Oman will be safe" if its own ports are threatened, Iranian state media said ahead of a proposed US blockade.

The US military said Sunday it will enforce a blockade on all traffic entering and leaving Iranian ports in the Strait of Hormuz from 10 a.m. ET Monday after the weekend's failed negotiations in Pakistan.

"Security of ports in the Persian Gulf and the Sea of Oman is either for everyone or for no one," a Revolutionary Guard spokesperson said, according to semi-official Iranian Students' News Agency (ISNA).

The spokesperson framed the US move as "illegal" and an example of "maritime piracy." As Iran...