The United States Friday condemned the attack in Libya that killed roughly 40 people and called on political parties to work together to form a new government. "This latest terrorist attack underscores the need for all Libyan parties ... to participate in the U.N.-led dialogue convened by Bernardino Leon, the special representative of the U.N. secretary-general, to form a national unity government," State Department spokeswoman Jen Psaki told reporters. "Those who choose not to participate are excluding themselves from discussions which are critical to combating terrorism, as well as to the overall peace, stability and security of Libya," Psaki said. Earlier Friday, militants claiming loyalty to the Islamic State killed 40 people when they blew themselves up in cars laden with explosives in eastern Libya.