Fox News strategic analyst Lt. Col. Ralph Peters (Ret.) warned this morning that Iran is building a new "Persian empire" in the Middle East. 

His comments come amid reports that Yemen's president and cabinet have stepped down in the face of advancing Iran-backed rebels. 

President Abed Rabbo Mansour Hadi, backed by the U.S., has been holed up in his palace for the last few days amid negotiations with the Shiite Houthi rebels.

Peters said President Obama "desperately" wants to make a nuclear deal with Tehran, and is ignoring "phenomenal changes" taking place in the Middle East. 

"Iran, under our noses, is building a new Persian empire. While we're focused on ISIS, and that's important to focus on, Iran is acting in Yemen, as we've seen in the last several days, backing Houthi rebels. Iran is acting in Syria, backing the Assad regime, It backs Hezbollah (in Lebanon), while our Air Force helps Iran's ground efforts in Iraq," said Peters. 

He said Iran is on track to take control of all or part of Iraq, western Afghanistan, Yemen, Syria and Bahrain. 

Peters responded to Joe Biden's statement that there's "no existential threat" to the U.S. from ISIS fighters in Iraq and Syria. 

Peters said that may be accurate for now, but noted that a nuclear-armed Iran will pose an existential threat to Israel and a "terrible, if not existential threat" to the U.S. 

Watch his analysis above.