WASHINGTON

The United States said on Thursday it is "increasingly concerned" by recent escalating Russian aggressions and troop movement on the border in eastern Ukraine.

White House spokeswoman Jen Psaki said Russia now has more troops on the border than at any time since 2014 and five Ukrainian soldiers have been killed this week alone.

"These are all deeply concerning signs," Psaki said at a news conference.

US officials are discussing concerns about increased tensions in cease-fire violations and regional tensions with NATO allies, she added.

Ukrainian Chief of General Staff Ruslan Homchak told parliament last month that Russia was sending troops near the border under the pretext of military drills. According to Kremlin spokesman Dmitry Peskov, the Russian Armed Forces does not pose a threat to Ukraine.

Ukraine has been plagued by conflict in its eastern regions since March 2014, following Russia’s illegal annexation of Crimea.

Fighting between Ukrainian government forces and pro-Russian separatists in eastern Ukraine has seen more than 13,000 people killed, according to the UN.