Trump denounces Barcelona terror attack in tweet The president added that the U.S. "will do whatever is necessary to help."

 -- President Donald Trump and Vice President Mike Pence each offered condemnation of the terrorist attack in Barcelona, Spain Thursday, and expressed that the United States is prepared to assist in efforts to pursue those found to be responsible.

"The United States condemns the terror attack in Barcelona, Spain, and will do whatever is necessary to help. Be tough & strong, we love you!" wrote Trump on Twitter Thursday afternoon.

A van drove into pedestrians on a boulevard and public square popular with tourists in Barcelona earlier in the day, leaving at least 13 people dead and more than 80 others injured — which law enforcement in the city labeled an act of terrorism.

Trump faced criticism over the weekend for not labeling a similar attack in Charlottesville, Virginia, as terrorism. In that attack, one woman died and 19 other people were injured when a car rammed into people demonstrating against a white nationalist rally in the city.

Attorney General Jeff Sessions told ABC News on Monday that the Charlottesville attack met "the definition of domestic terrorism."

From Panama, where he was traveling Thursday, Vice President Mike Pence expressed that "the latest scenes of carnage and and mayhem sicken us all."

"Whatever inspired today's terror attack, the United States stands ready to assist the people of Spain and find and punish those responsible," said Pence.

The president's and vice president's comments followed remarks earlier by Secretary of State Rex Tillerson, who offered the U.S.'s condolences and a strong warning to others who attempt to instigate attacks.

"Terrorists around the world should know the United States and our allies are resolved to find you and bring you to justice," said Tillerson.