Iran's government has denied an allegation by the US government that an Iranian drone attacked a Japanese-owned chemical tanker in the Indian Ocean.

On Saturday, the US Department of Defense said what it calls a one-way attack drone fired from Iran hit the tanker.

Iranian Foreign Ministry spokesperson Nasser Kanaani denied the allegation at a news conference on Monday, calling it worthless.

Kanaani went on to say that the US government is responsible for "the start of the Gaza war and its continuation for more than two-and-a-half months." He said the US government is not in a position to make accusations and claims against others.

Iran has also denied its involvement in attacks by Yemen's anti-government Houthi group on commercial vessels in the Red Sea in retaliation for Israel's attacks on Gaza.

On Saturday, the Iranian Revolutionary Guard Corps warned that if Israel continues with its killings, the United states and its allies "should wait for the birth of new powers of resistance and the closing of the rest of the waterways," including the Mediterranean Sea.