Iraq's parliament has approved new defense and interior ministers, filling the last open positions in the new government after weeks of delay.
Lawmakers on October 18 approved Muhammad Salim al-Ghabban, a Shi'ite deputy from Abadi's State of Law political bloc, to be interior minister.
Khalid al-Obeidi from the Sunni Arab bloc was named defense minister.
Obeidi is from the besieged city of Mosul.
The appointments of Ghabban and Obeidi come as Iraq faces its greatest crisis in more than a decade, with militants from the Islamic State (IS) extremist group occupying large swaths of territory in western and northern Iraq.
Speaking to reporters in Boston, U.S. Secretary of State John Kerry welcomed the announcement as a "very positive step."
Iraq's new unity government was sworn in on September 8, headed by Shi’ite Prime Minister Haidar al-Abadi, with Sunni Arab and Kurdish deputy prime ministers.
But the interior and defense posts had not been filled, as parliament rejected Abadi's original nominees.
The previous prime minister, Nuri al-Maliki, resigned in August amid accusations by the Sunni Arab and Kurdish communities that his administration was pursuing sectarian policies.
IS militants exploited discontent with Maliki's cabinet, gaining the backing of some Sunni Arab rebels.
Meanwhile, Iraqi government forces, supported by U.S.-led air strikes, continue to battle IS militants around Ramadi, the capital of the western province of Anbar, and the city of Tikrit in Salahuddin province north of Baghdad.
In the capital, bombing attacks killed dozens of people in recent days.
The U.S. military said its warplanes conducted 10 air strikes against IS targets in Iraq and 15 strikes in Syria on October 17-18.