Update: Iran plans to return the crewmen to a ship from the USS Truman carrier strike group on Wednesday.

JUST IN: Plans are in place for Iran to return U.S. sailors to U.S. Navy Wed. morning, gulf time, US defense official says - Reuters — CNBC Now (@CNBCnow) January 13, 2016

JUST IN: #Iran to return detained #US sailors to a ship from USS Truman carrier strike group: US defence official — The Straits Times (@STcom) January 13, 2016

So we suppose we can just call the sailors "State of the Union hostages". The rationale for waiting until tomorrow (i.e. until after Obama's speech): it's safer to carry out the exchange in daylight, according to an unnamed US official.

In short, the Ayatollah has just pulled off one epic publicity stunt.

* * *

Tensions were already running high between Tehran and Washington in the wake of Iran's move to test-fire a next generation surface-to-surface ballistic missile with the range to hit Israel.

And then the IRGC conducted a live-fire rocket test within 1,500 yards of a US aircraft carrier in the Strait of Hormuz.

Now, in a further escalation, Iran has reportedly seized two US Navy ships.

2 U.S. NAVY BOATS IN IRANIAN CUSTODY, PENTAGON SAYS: AP

RHODES SAYS U.S. WORKING ON RETURN OF CREW

RHODES SAYS U.S. WORKING TO RESOLV

But nobody panic, because Iran has promised to return the crew "promptly" and as CNN adds, according to Iran the sailors are safe:

.@PressSec: "We have received assurances from the Iranians that our sailors are safe" https://t.co/GV9hdWZy3P https://t.co/1ioOtqYVH4 — CNN (@CNN) January 12, 2016

That appears to contradict a statement from Fars which says the US has "repeated" calls for the crew's release.

AP writes that the Pentagon says it briefly lost contact with two small Navy craft in the Persian Gulf on Tuesday but has received assurances from Iran that the crew and vessels will be returned safely and promptly.

Pentagon says these photos show examples of the type of craft involved in Iran incident pic.twitter.com/47ClLilOZK — Oliver Darcy (@oliverdarcy) January 12, 2016

"Riverine command boats or RCBs, are actually Swedish CB-90s and are a type of fast attack craft," WaPo notes, adding that "in a number of pictures released by the U.S. Navy, the boats are outfitted with a number of light, medium and heavy weapons including .50 caliber heavy machine guns and GAU-19 miniguns."

"RCB’s can carry contingents of infantry and special operation forces and are often crewed by sailors in Riverine squadrons, known by some as River Rats," WaPo continues. "The riverine force came of age in the Vietnam War in what was then known as the Brown Water Navy. In the 1960s and early 1970s boats such as Patrol Boat, River (from ‘Apocalypse Now’ fame) and Swift Boats were the River Rats vessels of choice."

Pentagon spokesman Peter Cook tells The Associated Press that the boats were moving between Kuwait and Bahrain when the US lost contact with them.

Cook says, "We have been in contact with Iran and have received assurances that the crew and the vessels will be returned promptly."

The crews, which total 10 Navy sailors, are being held at Farsi Island, a highly restricted island between Bahrain and Kuwait, where Iran has a naval base. US officials are saying it is unclear how the crew members ended up in Iranian waters, though Secretary of State John Kerry has kept phone contact with Iranian officials in Tehran, urging for a release. A senior official told NBC News the Iranians understand a mistake was made and have agreed to a release to come in hours.

According to AP, an anonymous senior official says Kerry "personally engaged with” Iranian Foreign Minister Javad Zarif to work out a solution almost immediately upon hearing of the development around 12:30 pm EST.

Josh Earnest, the White House spokesperson, said the sailors will be released "promptly" and " allowed to continue their journey."

The international incident comes on the day President Obama will give his final State of the Union speech of his tenure. Obama's political opponents are capitalizing on the timing, especially since the International Spectator, citing Iran Revolutionary Guard, reports that "seized US sailors will not be released tonight or before State of the Union address."

Senator Tom Cotton (R-Arkansas) told CNN, "senior members of Barack Obama's administration are apologizing for Iran seizing two US Navy vessels and holding 10 sailors hostage. The White House tonight is a hot bed of cold feet."

Presidential candidates Dr. Ben Carson and Jeb Bush have taken to Twitter to criticize Obama's reaction. Bush called for "no more bargaining" and an immediate return home for the sailors, whereas Carson took a shot at Obama's "preparing to talk about his so called 'accomplishments'" in reference to tonight's national address.

If our sailors aren’t coming home yet, they need to be now. No more bargaining. Obama’s humiliatingly weak Iran policy is exposed again. — Jeb Bush (@JebBush) January 12, 2016

BREAKING: While POTUS is preparing to talk about his so called "accomplishments", 10 of our American sailors are being held by #Iran. — Dr. Ben Carson (@RealBenCarson) January 12, 2016

This marks the second time in as many weeks that the President's "soft" policy on Iran has come under fire. Following the abovementioned rocket incident GOP lawmakers called for fresh sanctions on Tehran in connection with two ballistic missile launches in October and November. The White House was apparently prepared to announce a new set of measures aimed at around a dozen individuals and companies but at the last minute, the administration backed out. Obama's cold feet came after President Rouhani ordered the defense ministry to accelerate the country's ballistic missile program in the event new sanctions were put in place.

Meanwhile, according to Iran's version of today's events, Fars News agency says US sailors picked up by Revolutionary Guard Corps, from hardline camp who are opposed to the nuclear deal. Fars adds that the sailors were detained for illegally and "intentionally" entering Iranian waters even though they knew the area well. Tehran also contends the US ships were having "technical difficulties."

Fars News says IRGC detained 10 US military personnel in 2 boats for illegally entering Iranian waters in Gulf https://t.co/daqeCflOrM — Borzou Daragahi (@borzou) January 12, 2016

Fars says US sailors know area, carrying GPS, intentionally entered Iran's territorial waters — Sobhan Hassanvand (@Hassanvand) January 12, 2016

Fars: Both US boats "illegally" entered 2 km into Iranian waters, and IRGC confirms this info on their GPS record. https://t.co/V266Fsx42h — FDD's Iran Project (@FDD_Iran) January 12, 2016

Just in: Iran's Fars news agency says 10 US sailors held include one woman — Jim Sciutto (@jimsciutto) January 12, 2016

#Iran Questions: - Kuwait to Bahrain is 300 nautical miles. Why were US sailors traveling by small boats? Joy ride? https://t.co/xmRCY6Or36 — Tarek Fatah (@TarekFatah) January 13, 2016

And here is the full Fars statement, google translated:

According to defense Fars News Agency, Iranian Revolutionary Guards 10 US military with two boats illegally entered Iranian waters in the Persian Gulf had been detained. According to the information received by the Fars news agency every American boat is equipped with 3 machine guns caliber 50 (one in front and two on the sides of the float). The two vessels illegally entered and patrolled about 2 km deep inside Iranian waters, and the information recorded on their GPS device and is now in the hands of Iranian Revolutionary Guards. The military said among the arrested were 9 men and one woman. They carried heavy weapons in their vessels. US officials repeated calls for the release of prisoners will continue with Tehran.

So, they are prisoners, and unlike the White House tried to spin it, guests of honor?

Ironically, earlier we asked:

Is Iran going to wait until the end of the SOTU address before returning the 10 sailors? — zerohedge (@zerohedge) January 12, 2016

We now have the answer: