"It is time to launch a decisive battle against terrorism," Maliki said after Saturday's meeting attended by David Petraeus, the US commander in Iraq, and Muwaffaq al-Rubaie, Iraq's national security advisor.
"The battle that our armed forces will launch will destroy terrorism and the criminal gangs and outlaws in Nineveh," Maliki said.
Recent attacks in Mosul have killed dozens of people, including a police chief.
On January 25, Maliki promised a "decisive battle against al-Qaeda".
The panic buying intensified after military reinforcements arrived in the city a few days ago.
Abu Karim, a 49-year-old grocer, said: "I sold in one week what I usually sell in a month. The rush is continuing."
Salem Ahmed, a petrol seller, said prices had doubled because people were stockpiling.
"People are trying to buy as much petrol for their cars and kerosene for heating and cooking as they can," he said.
Mosul has been included as a target in the US' Operation Phantom Phoenix according to the American military.
The operation, which was launched on January 8, is a nationwide assault on al-Qaeda.
Scott Rye, a US military spokesman, said: "Coalition forces recognise the strategic importance of Mosul to al-Qaeda in Iraq and our operations will continue in the area."
Mosul is Iraq's third-largest city, 360km northwest of Baghdad.
Many fighters shifted to northern Iraq, including Mosul, to escape the US-led offensives in and around Baghdad and in Diyala province, northeast of the capital.
US commanders in northern Iraq have said the battle to oust them from Mosul will not be a swift strike as al-Maliki suggested, but rather a grinding campaign that will require more firepower from both the Pentagon and Iraqi allies.