Iran announced Monday that it has tested a new weapon capable of sinking ships nearly 200 miles away, and reiterated threats to close a strategic waterway at the mouth of the Persian Gulf if attacked.
Up to 40 percent of the world's oil passes through the Strait of Hormuz, a narrow passage along Iran's southern coast. Tehran has warned it could shut down tanker traffic there if attacked - a move likely to send oil prices skyrocketing, the AP reported.
The warnings came two days after a deadline expired for Iran to respond to incentives from six world powers, offered in exchange for a promise to curb its uranium enrichment.
Later Monday, the U.S. State Department said the group - the five permanent members of the U.N. Security Council, plus Germany - agreed to pursue further sanctions against Iran because of its failure to meet the Saturday deadline.
Iran and the West have been mired in a standoff over the country's disputed nuclear program. The United Nations has already slapped Iran with three rounds of sanctions, over its refusal to stop enriching uranium - a key process that generates either fuel for a nuclear reactor, or the fissile material for a bomb.
Iran says its nuclear program is for peaceful purposes only, to generate electricity.
Revolutionary Guards commander Gen. Mohammad Ali Jafari said Monday that the new marine weapon is "unique in the world" and has a range of 300 kilometers ( 186 miles), according to the state news agency IRNA.
That's within range of U.S. warships deployed in the Persian Gulf. Last month, Iran tested missiles it claimed were capable of reaching 1,250 miles ( 2,000 kilometers) away - putting U.S military bases in the Middle East as well as Israel, Turkey, the Arabian peninsula, Afghanistan and Pakistan all within striking distance.
Monday's report gave no details on when or where the new weapon was tested. Its range indicates it could be a type of torpedo, but state radio called it a missile.
Jafari warned Iran would respond decisively if any military strike is carried out against it.
"Enemies know that we are easily able to block the Strait of Hormuz for an unlimited period," he was quoted by state radio as saying. "The strait and vessels are in range of our various weapons."
Both the U.S. and Israel - which shares American concerns over Iran's nuclear program - have said they would prefer a diplomatic solution to the standoff with Iran, but have not ruled out other options - including a military one.
Israeli analyst Ephraim Kam, a former senior intelligence officer, dismissed the new weapons test.
"They are always boasting about their weapons and their military capabilities and saying how unique they are, but they are usually just standard military weapons," he said.