Premier Romano Prodi resigned Wednesday after an embarrassing loss in the Senate on foreign policy.

Prodi aides said consultations will begin shortly among politicians, and they didn't rule out that the president would ask Prodi to try to form a new government.

Infrastructure Minister Antonio Di Pietro had told reporters that President Giorgio Napolitano could accept it or ask him to remain in power.

Prodi earlier arrived at the presidential palace to consult with Napolitano immediately after the premier briefed ministers about his intentions at a Cabinet meeting, Di Pietro said.

The vote in the upper house was not binding, but Foreign Minister Massimo D'Alema said earlier that the government should resign if it lost. Before the Cabinet meeting, some of his allies said it was unclear whether there was enough agreement among the widely divergent ranks to continue to hold on to power.

Conservative leader Silvio Berlusconi was among the opposition forces clamoring for Prodi to step down after the center-left fell two votes short of the majority needed to approve the foreign policy motion.

"Foreign police involves the role and image of Italy in the world and the life of our soldiers committed to international peace mission," Berlusconi said, insisting that Prodi, who defeated him in elections last year, had an "obligation" to resign.

Seconds after the result was announced by the Senate speaker, opposition lawmakers applauded and chanted "Resign!"

The government needed 160 votes to win backing from the upper house for its foreign policy program. It received 158 votes; 136 members of the conservative opposition voted against it, and 24 abstentions — equivalent to a "no" vote in the Senate — caused the government to lose.

Italy has 1,800 troops in Afghanistan, which were sent in by former Premier Silvio Berlusconi. The current government has agreed to keep the troops there, sparking opposition from its own Communist allies.