Sharon Reich-Garson

Hi, I'm your weekend host, Sharon Reich-Garson.

It's Saturday, February 14th.

Today, the U.S.

prepares for possible military operations against Iran.

Rubio pushes a unity message in Munich.

Plus, Rio kicks off carnival with massive street parties.

This is Reuters World News, bringing you everything you need to know from the front lines in 10 minutes, seven days a week.

We start with a Reuters exclusive.

The United States is preparing for the possibility of weeks-long military operations against Iran as President Trump sends a second aircraft carrier to the Middle East.

Two U.S.

officials tell Reuters on the condition of anonymity that an attack could become a far more serious conflict than previously seen between Washington and Tehran.

That disclosure raises the stakes for the diplomacy now underway, with U.S.

and Iranian envoys preparing for another round of talks in Geneva next week.

At the same time, President Trump is embracing potential regime change in Iran.

Iran has warned that in case of strikes on its territory, it could retaliate against any U.S.

military base in the Middle East.

Asked for comment on the preparations for a potentially sustained U.S.

military operation, White House spokesperson Anna Kelly said, quote, President Trump has all options on the table with regard to Iran.

Over to Munich now, where U.S.

Secretary of State Marco Rubio is striking a more unifying tone, telling European leaders that Washington isn't walking away from the transatlantic alliance.