Fighting back tears following the Brussels attacks, EU's foreign policy chief abruptly walked out of a news conference in Jordan on Tuesday after saying that "today is a difficult day."

Federica Mogherini was wrapping up her opening statement at a joint news conference with Jordanian Foreign Minister Nasser Judeh when she was overcome by emotion.

When Judeh resumed speaking, she walked over to him, whispered "I'm sorry," and briefly embraced him. The two then walked off the stage.

At least 31 people were killed when bombs exploded at the Brussels airport and one of the city's metro stations earlier in the day.

Mogherini said in her opening remarks in Jordan that it was a "very sad day for Europe, as Europe and its capital are suffering the same pain that this region has known and knows every single day, being it in Syria, being it elsewhere."

She also praised Jordan as a defender of moderate Islam.