Good morning and welcome to Fox News First. Here's what you need to know as you start your Friday ...

Iran vows vengeance after US airstrike kills top Iranian general
Iran's Supreme Leader Ayatollah Ali Khamenei on Friday warned that a "harsh retaliation is waiting" for the U.S. after an airstrike on an airport in Baghdad killed Iranian Gen. Qassem Soleimani, the head of Iran's elite Quds Force.

The Pentagon confirmed that President Trump ordered the attack that killed Soleimani, a military mastermind whom Secretary of State Mike Pompeo had deemed equally as dangerous as ISIS leader Abu Bakr al-Baghdadi, who killed himself in October during a U.S. raid on a compound in northwest Syria. Khamenei declared three days of public mourning for the general's death. (Who was Soleimani? Click here to learn more.)

The deadly attack comes amid tensions between Washington and Tehran after a New Year's Eve attack by Iranian-backed militias on the U.S. Embassy in Baghdad. In response, the Pentagon had launched its own offensive and announced it would deploy 750 Army troops to the region. Click here for more on our top story.

Democratic presidential candidate former Vice President Joe Biden addresses a gathering during a campaign stop in Exeter, N.H., Monday, Dec. 30, 2019. (AP Photo/Charles Krupa)

Democratic presidential candidate former Vice President Joe Biden addresses a gathering during a campaign stop in Exeter, N.H., Monday, Dec. 30, 2019. (AP Photo/Charles Krupa)

2020 Dems, Dem lawmakers admit Americans won't mourn Soleimani but slam Trump anyway
Trump didn't comment immediately about the airstrikes but tweeted a photo of the American flag. Both Democrats and Republicans said the world was better off without Soleimani, but 2020 presidential candidates and Democratic leaders still attacked Trump over airstrikes.

House Speaker Nancy Pelosi, House Intelligence Chairman Adam Schiff, Sen. Chris Murphy, D-Conn., Sen. Ed Markey, D-Mass. and others complained that Trump did not consult Congress before ordering the airstrikes and said Americans do not want a war with Iran. Former Vice President Joe Biden claimed that by ordering the airstrike Trump “just tossed a stick of dynamite into a tinderbox.” Trump, Biden said, owes the American people an "explanation of strategy" and plan to keep our troops safe.

Alex Trebek discusses final 'Jeopardy!': I will need 30 seconds
“Jeopardy!" host Alex Trebek already has some idea of what he is going to tell the show's audience on the day of his final taping, whenever that may be. In an interview with ABC's Michael Strahan on Thursday evening, Trebek said he'll ask the game show's director to leave him 30 seconds at the very end. Click here for more.

MAKING HEADLINES:
ICYMI: Trump campaign blows past 2020 Dems with latest fundraising haul, sitting on over $100M.
Marianne Williamson lays off her entire presidential campaign staff.
McCabe apologized for misleading investigators on leak, transcripts show.

CLICK HERE TO GET THE FOX NEWS APP

TODAY'S MUST-READS
NBC's Tom Brokaw says he's 'very, very fortunate' after fire erupts in his NYC building.
Reporter's Notebook: How the growing national debt seems to be fading from concern in DC.
Could Roe v. Wade be overturned? Lawmakers sign amicus brief ahead of key Supreme Court case

THE LATEST FROM FOX BUSINESS
Stocks drop, oil jumps after US airstrike kills Iranian general.
Lowe's to hire thousands for spring season
These businesses will be biggest moneymakers this year, report predicts. 
 
#TheFlashback: CLICK HERE to find out what happened on "This Day in History."
 
SOME PARTING WORDS

Sean Hannity, on break for the Christmas holiday season, called into his own program Thursday night and said President Trump and the military are on high alert after U.S. airstrikes killed Iranian Gen. Qassim Soleimani and that he is told that "every option is on the table."

Not signed up yet for Fox News First? Click here to find out what you're missing.

Click here to find out what's on Fox News and Fox News Radio today!
 
Fox News First is compiled by Fox News' Bryan Robinson. Thank you for making us your first choice in the morning! Enjoy your day and weekend! We'll see you in your inbox first thing Monday morning.