In a move to counter Moscow's influence in Ukraine, the US has announced $200 million in security assistance to Kiev. The aid will fund additional training, equipment and advisory efforts to build the defensive capacity of Ukraine's forces, the Pentagon said in a statement on Friday. "This reaffirms the long-standing defence relationship between the US and Ukraine," the statement noted, adding that Washington's security assistance to Kiev totalled more than $1 billion since 2014. The Pentagon statement came after the White House on Friday rejected a proposal from Russia to hold a referendum in eastern Ukraine on the fate of the region, Xinhua news agency reported. Russian President Vladimir Putin raised the possibility of a referendum in Ukraine during his meeting with US President Donald Trump on Monday in Helsinki, Finland, Russia's Ambassador to the US Anatoly Antonov said. The conflict in eastern Ukraine started in 2014 between the government forces and armed groups that declared independence from Kiev. Ukraine has long accused Russia of aiding the insurgents while Moscow has repeatedly dismissed Kiev's claims. "To organise a so-called referendum in a part of Ukraine which is not under government control would have no legitimacy," the White House National Security Council said Friday.