"We are getting information that three warships are tracking the pirates and two of them are very close to the hijacked ship," he said.
"One of these ships is from the United States and the two other ones are from the European Union countries."
A tribal chief and fishermen in the Haradhere region said they had seen the Faina surrounded by at least two ships.
The Faina was seized from the control of its 21-strong crew on Thursday while sailing towards the Kenyan port of Mombasa.
In addition to the T-72 battle tanks, the military consignment contains grenade launchers and ammunition for the Kenyan army.
The Faina has headed towards Haradhere, an city in central Somalia controlled by the Islamic Courts' Union (ICU), a group which is fighting against the transitional government based in Mogadishu.
However, it is not clear who is in control of the vessel.
The pirates are demanding that a $35 million ransom be to release the seized vessel and its crew.
Pottengal Mukundan, director of the International Maritime Bureau and head of the Kuala Lumpur-based Piracy Reporting Centre, said that a firm response was needed to discourage further pirate attacks.
"They are young Somalis, based along the east coast of Somalia, who are looking for an easy way to make a lot of money," he said.
"They are reasonably well financed and they have a lot of equipment. There are possibly 10 or these gangs operating at any time."
Somali pirates typically take vessels they capture to the Eyl region, about 800km from Mogadishu, so the choice of Haredhere marks a departure for the rebels.
The military hardware on board the Faina was among the last of a series of shipments to Kenya, Valery Konovalyuk, head of a parliamentary committee that oversees Ukraine's arms deals, said.
The Russian frigate Neustrashimy was despatched to the Horn of Africa region on Friday in the wake of the seizure of the Faina.
Igor Dygalo, Russia's Navy spokesman, said the frigate was sent out due to "the rise in pirate attacks, including against Russian citizens".
"In the future, the Russian navy will send its ships on a regular basis to zones where there is a danger from maritime piracy," Dygalo told Russia's Vesti-24 television station.
The Somalian coast has been a favoured region for pirates amid years of continuing instability across the country.
The nation has witnessed fierce fighting and lawlessness since Mohamed Siad Barre was removed from the Somalian presidency in 1991.