US President Barack Obama has pledged to stand with Ukraine in its dispute with Russia.
The comments from Obama came as he welcomed Ukraine's interim prime minister to the White House.
According to the BBC, Obama warned Russian President Vladimir Putin that the international community 'will be forced to apply costs' if Moscow a does not remove its troops from Crimea.
Ukrainian PM Arseniy Yatsenyuk, speaking after meeting Obama, said Ukraine 'will never surrender' to Russia.
Obama said the US has been very clear that Russia's incursion into Crimea outside of its bases to be a violation of international law, the report added.