Updated

Ukraine's former prime minister Yulia Tymoshenko says the West must ramp up pressure on Russia to force it to withdraw troops from Crimea.

Speaking to The Associated Press on Wednesday, two weeks after she was released from jail, 53-year-old Tymoshenko said Ukraine should not make any compromises to appease Russia.

"We believe that the aggressor must leave without any conditions," Tymoshenko told AP.

Tymoshenko, whose jailing was denounced by the West as politically motivated, said that any negotiations about Ukraine's future should be conducted directly with the United States, Britain and Russia, who signed a treaty in 1994 guaranteeing Ukraine's security.

The West must do "everything that will stop the aggressor. Period," she said.