Jerusalem - The inauguration of Barack Obama as president of the United States is a great day for the US because his "most unusual hope and election, only ten years ago, would have been unimaginable," Israeli President Shimon Peres said Tuesday.

"What made history ugly, unmistakably, was basically slavery and there were two sorts of slavery: men upon women and white upon black," Peres said.

"In the 20th century there was a liberation of women. In the 21st century, there is a liberation of the other kind of slavery, of one colour upon another colour because of the difference in colour," he said.

Peres said he prayed that Obama would be a great president because "if he will be a great President of the United States, he will serve all humankind, all nations and all persons."

"You be a great American President today means to struggle for peace, to fight terror, to correct the environment, and to offer the young generation a better future," Peres added. (dpa)