French President Emmanuel Macron voiced solidarity with Spain on Thursday after a deadly van rampage in Barcelona.
"We remain united and determined," Macron said on Twitter, describing it as a "tragic attack" and saying his thoughts were with the victims.
The office of German Chancellor Angela Merkel on Thursday condemned the "revolting attack" in Barcelona, which saw a van plough through a street packed with pedestrians, killing 13 people.
"We are thinking with profound sadness of the victims of the revolting attack in Barcelona -- with solidarity and frienship alongside the Spanish people," tweeted spokesman Steffen Seibert.
Russian President Vladimir Putin called Thursday for the world to unite in an "uncompromising battle against the forces of terror" the Kremlin said.
"We decisively condemn this cruel and cynical crime against civilians," Putin wrote in a telegram of condolences to Spanish King Felipe VI.
"What happened once again confirms the need for a genuine unification of efforts by the entire world community in an uncompromising battle with the forces of terror," Putin said.
President Donald Trump tweeted: "The United States condemns the terror attack in Barcelona, Spain, and will do whatever is necessary to help. Be tough & strong, we love you!"
Secretary of State Rex Tillerson added: "Terrorists around the world should know -- the United States and our allies are resolved to find you and bring you to justice."
At least 13 people were killed Thursday when a driver deliberately slammed a van into crowds on Barcelona's most popular street in what police said was a "terror attack".
The attack, the latest in a wave of vehicle rammings across Europe in recent years, caused panic on the streets of Spain's largest city and drew condemnation from world leaders.
The famous Las Ramblas is one of Barcelona's busiest streets, lined with shops and restaurants and normally thronged with tourists and street performers until well into the night.
"All at MCFC are saddened to hear of the attack in the City of Barcelona. Our thoughts are with all affected and the emergency services." - Manchester City manager Pep Guardiola, a former Barcelona midfielder and coach.
"Shattered by what has happened in Barcelona! All my support for the families affected and the city." - Spanish tennis champion Rafael Nadal, whose uncle Miguel Angel Nadal used to play for Barcelona
