WASHINGTON, January 13. /TASS/. US President Joe Biden said the US will respond to the Yemen-based Houthis if they continue to attack merchant ships in the Red Sea.

"We will make sure that we respond to the Houthis if they continue this outrageous behavior," the president said, according to the White House press pool.

Reuters reported that Biden called the Houthis a "terrorist" group as he talked to members of the news media.