Earlier Wednesday, Somali Ambassador to Russia Mohamed Handule said his country's President Abdullahi Yusuf Ahmed had authorized Russia's military to fight pirates off Somalia's coast and on land.
"This permission allows the warship to use the whole range of the weapons on board," the Navy official said. "We are not excluding a takeover of the vessel by force to free the crew, which includes Russian citizens."
Ukraine's Foreign Ministry earlier cited the Faina's owner, Tomax Team Inc., as saying there were three Russians, 17 Ukrainians and one Latvian on board the ship when it was seized.
However, Nyna Karpachyova, the Ukrainian parliament's human rights ombudsman, said that the real owner of the ship, which was carrying 33 T-72 tanks and other military equipment, was an Israeli citizen, Vadim Alperin.
Karpachyova also said that relatives of the hostages on board the ship would ask the Ukrainian government to prevent the liberation of the Faina by force.
The pirates said earlier that they would kill a hostage if an attempt was made to free the hostages by force. The ship's captain, Russian Vladimir Kolobkov, earlier died of a heart attack.
Russia's Navy sent the Neustrashimy missile frigate to waters off the Somali coast to fight piracy and protect Russian vessels in the region on September 24.
The ship's armament includes SS-N-25 Switchblade anti-ship missiles, SA-N-9 Gauntlet SAM, a 100-mm gun, torpedoes and depth charges. The frigate also carries a Ka-27 ASW helicopter.
Pirates are increasingly active in the waters off Somalia, which has no effective government and no navy to police its coastline. The International Maritime Bureau said more than 30 incidents of piracy were registered in the region in 2007. More than 30 attacks have been committed so far this year off the coast of the East African nation.