Bloemfontein, South Africa - Spain coach Vicente Del Bosque defined Wednesday's shocking 2-0 defeat against the United States in the semi-finals of the Confederations Cup in South Africa as "an accident."

"This is an accident, a small step back. We have to look to the future with optimism," Del Bosque said at the end of a winning streak of 15 consecutive matches.

Serene, and often smiling, Del Bosque - whose men had not lost a game since November 2006 - was very generous in his praise of the United States, who got a historic win.

"It is a team that has played with a lot of energy, in counter- attack. Very fast players, who have made trouble for us. As a team they have defended well and they have counter-attacked very well," he said.

"It is not good to lose," Del Bosque admitted. "But we were not used to losing. We have to think about next season with a view to cementing our place in the World Cup."

Del Bosque explained the changes he made in the second half, some of which caused disappointment in his team.

"We have tried to open the field a little bit, it was difficult to go in down the middle. Not because Cesc (Fabregas) or (Albert) Riera were playing badly, we wanted to build a couple with Sergio Ramos down the right," he said of Fabregas' replacement with Santi Cazorla.

"In Riera's case, he had made a great effort, I was looking for Juan Mata's fine touch to end attacking situations better," he said.

"We have had a strong rival, who held their ground against us," Del Bosque summarized.

The coach had warned Tuesday of the United States' speed and their counter-attacking vocation.

"We had made a good analysis of the rival," he stressed. "We have missed that final touch in the forward line, and they have been a wall. I would almost, almost, put it in their defence's credit side, rather than in our strikers' debit side."

Still, Del Bosque thinks European champions Spain still deserve to be regarded as the best national team in the world.

"I have never liked that definition, because with powers like Brazil, Germany... But it's true that the FIFA ranking shows us first, and that is an objective fact," he said.(dpa)