Sigmar Gabriel (1st R), leader of the Social Democratic Party (SPD), speaks during a press conference in Berlin, Germany, on Dec. 14, 2013. An internal vote of Germany's Social Democratic Party (SPD) approved a coalition deal with Chancellor Angela Merkel's conservatives, SPD leaders announced on Saturday afternoon. (Xinhua/Zhang Fan)

Sigmar Gabriel (C), leader of the Social Democratic Party (SPD), speaks during a press conference in Berlin, capital of Germany, on Dec. 14, 2013. Germany's SPD approved the party's deal with Chancellor Angela Merkel's conservatives on forming a "grand coalition" government, results of a binding members' ballot showed on Saturday. (Xinhua/Zhang Fan)

Sigmar Gabriel, leader of the Social Democratic Party (SPD), speaks during a press conference in Berlin, capital of Germany, on Dec. 14, 2013. Germany's SPD approved the party's deal with Chancellor Angela Merkel's conservatives on forming a "grand coalition" government, results of a binding members' ballot showed on Saturday. (Xinhua/Zhang Fan)

Sigmar Gabriel (front C), leader of the Social Democratic Party (SPD), speaks during a press conference in Berlin, capital of Germany, on Dec. 14, 2013. Germany's SPD approved the party's deal with Chancellor Angela Merkel's conservatives on forming a "grand coalition" government, results of a binding members' ballot showed on Saturday. (Xinhua/Zhang Fan)

Andrea Nahles (L), Secretary General of the Social Democratic Party (SPD), hugs her colleague after a press conference in Berlin, capital of Germany, on Dec. 14, 2013. Germany's SPD approved the party's deal with Chancellor Angela Merkel's conservatives on forming a "grand coalition" government, results of a binding members' ballot showed on Saturday. (Xinhua/Zhang Fan)

Sigmar Gabriel (front R), leader of the Social Democratic Party (SPD), speaks during a press conference in Berlin, capital of Germany, on Dec. 14, 2013. Germany's SPD approved the party's deal with Chancellor Angela Merkel's conservatives on forming a "grand coalition" government, results of a binding members' ballot showed on Saturday. (Xinhua/Zhang Fan)

Sigmar Gabriel, leader of the Social Democratic Party (SPD), applauds during a press conference in Berlin, capital of Germany, on Dec. 14, 2013. Germany's SPD approved the party's deal with Chancellor Angela Merkel's conservatives on forming a "grand coalition" government, results of a binding members' ballot showed on Saturday. (Xinhua/Zhang Fan)