The gathering at the government headquarters followed a chaotic day that saw the Senate vote to impeach President Dilma Rousseff, suspending her from office and abruptly ousting nearly her entire government, a move she branded "a coup."
Temer moved quickly to announce his new team, whose star appears to be Finance Minister Henrique Meirelles, widely respected for serving as Central Bank chief during the boom years from 2003 to 2010.
He also promised to support the widening investigation into corruption at the state oil company that has already ensnared leading politicians from a variety of parties and even implicated Temer himself as well as several members of the new Cabinet.
His choice of ministers also raised criticism for its makeup: All its members are middle-aged or elderly white men - a particularly sore point in this majority non-white country. Six women, including one black, were included in the 39 members of Rousseff's Cabinet when she began her second term last year.
"This is not a moment for celebrations, but one of profound reflection," he said. "It's urgent to pacify the nation and unify the country. It's urgent for us to form a government of national salvation to pull this country out of the serious crisis in which we find ourselves."
Rousseff, however, vowed to fight her ouster, calling it "a coup" led by a social and economic elite that had been alarmed by the policies of her leftist Workers' Party, which had held power for 13 years.