(Adds more quotes, details)
KIEV, March 3 (Reuters) - Ukraine's acting president said on Monday Russia's military presence was growing in the Crimea region and urged Moscow to halt what he called aggression and piracy.
Oleksander Turchinov said the situation was "difficult" in some regions in the south and east of the country, where there are many Russian speakers, but that the Ukrainian authorities had matters there under control.
He also said Russia's Black Sea Fleet had trapped Ukrainian navy vessels in the bays of Sevastopol, the Crimean port where the Russian fleet has a base.
"The situation in Crimea remains tense and Russia's military presence is growing," Turchinov told a news briefing. "I appeal to Russia's leadership - stop the provocative actions, aggression and piracy. This is a crime and you will answer for it."
He gave no details of Russia's growing military presence in Crimea, where Russian forces are now in charge.
On the eve of a visit by U.S. Secretary of State John Kerry, Turchinov appealed for outside help.
"Form the world's leading countries we are awaiting not only moral support but also real help," Turchinov said.
An International Monetary Fund mission is also due to start work in Ukraine on Tuesday. Kiev hopes for an at least $15-billion loan package from the IMF to avert bankruptcy.
(Reporting By Pavel Polityuk, Editing by Timothy Heritage)