U.S. flies B-52 bombers over Persian Gulf as show of force against Iran

What they're saying: The head of U.S. Central Command Gen. Frank McKenzie said the mission was a defensive move.

• “The United States continues to deploy combat-ready capabilities into the U.S. Central Command area of responsibility to deter any potential adversary, and make clear that we are ready and able to respond to any aggression directed at Americans or our interests,” said Gen. Frank McKenzie, the commander of Central Command, said, according to AP.
• “We do not seek conflict, but no one should underestimate our ability to defend our forces or to act decisively in response to any attack.”

The big picture: The U.S. has considered closing its embassy in Baghdad after a recent series of rocket attacks on Iraq's Green Zone that the U.S. blames on Iranian-backed militias.

• On Dec. 23, President Trump tweeted, "Some friendly health advice to Iran: If one American is killed, I will hold Iran responsible. Think it over."

• Iran has denied any involvement in the recent attacks.

The two countries are also approaching the Jan. 3 anniversary of the U.S. killing of top Iranian military commander Gen. Qassem Soleimani.

• There is growing concern in the Trump administration that Iran plans to avenge the killing of Soleimani, according to AP.
• “Trump will bear full responsibility for any adventurism on his way out,” Iranian Foreign Minister Javad Zarif tweeted last week.

Go deeper: U.S. considering closing Iraqi embassy after rocket attack