PARIS -- France's top security official publicly dressed down the United States at the American ambassador's July 4 garden party, denouncing alleged U.S. "espionage" of France and other countries, while the European Parliament voted to open an investigation.

Interior Minister Manuel Valls was guest of honour at the fete hosted by Ambassador Charles Rivkin Thursday. In a speech before hundreds of guests, he said that "in the name of our friendship, we owe each other honesty. We must say things clearly, directly, frankly."

He said that President Francois Hollande's demand for clear and precise explanations about reports of U.S. spying are justified because "such practices, if proven, do not have their place between allies and partners."

Later Thursday, Valls said France had rejected an asylum request from National Security Agency leaker Edward Snowden.

In a statement, Valls said the request, received via the French embassy in Moscow, had been rejected after "taking into account a legal analysis and the situation of" Snowden.

In Strasbourg, the European Parliament agreed to start an investigation into the allegations that European Union offices were among those bugged and called for more protection for whistleblowers.

European countries agreed Wednesday that planned talks on free trade with the U.S. must start in parallel with discussions on National Security Agency surveillance. Those talks are still on track to begin next week.