Marcelo Rebelo de Sousa and António Costa were in Barcelona to take part in a ceremony for the victims of the attack, among whom were two Portuguese nationals. A total of 15 people died and hundreds of others were injured when a van ploughed into crowds of tourists along the busy Las Ramblas Street.
The funerals of the two Portuguese women killed in the Barcelona terrorist attack were held on Wednesday.
The bodies of the two women were handed over to their families on Sunday and were flown out of Barcelona to Portugal on a Portuguese air force plane that the government provided for the purpose.
The two Portuguese nationals were a 74-year-old woman who lived near Lisbon and her 20-year-old grand-daughter who lived in London.
The fugitive, who mowed down scores of tourists in Barcelona then stole a car and killed its owner as he made his getaway, has been shot dead, Spanish authorities said as they raised the death toll in the attacks to 15.
Younes Abouyaaqoub, 22, has been the target of an international manhunt since last Thursday’s van attack in Barcelona.
Authorities say they now have evidence he drove the van that ploughed down the city’s famed Las Ramblas promenade.
Another vehicle attack early on Friday by other members of his extremist cell killed one person and wounded several others in the coastal town of Cambrils.
That ended in a shootout with police, who killed five attackers.
The Islamic State group has claimed responsibility for both attacks.
Regional authorities said 50 people are still in hospital from both attacks, nine of them in a critical condition.
Catalonia’s regional president, meanwhile, said regional and local authorities rejected the Spanish government’s suggestion to place traffic barriers to protect the Las Ramblas promenade because it deemed them “inefficient”.
Carles Puigdemont told La Sexta television the barriers would not have prevented vehicles from entering the promenade at other points - and he said closing off Las Ramblas was impractical because emergency vehicles still needed access.