Blinken said in a statement the decision was taken out of concern for the safety of embassy staff.
Most embassy staff have already been ordered to depart Ukraine and US citizens have been advised to leave the country.
“My team and I constantly review the security situation to determine when prudence dictates a change in posture.” Blinken said.
“With that in mind,we are in the process of temporarily relocating our Embassy operations in Ukraine from our Embassy in Kyiv to Lviv due to the dramatic acceleration in the buildup of Russian forces.”
The Wall Street Journal reported that the State Department ordered the destruction of networking and computer equipment at the Kyiv embassy.
Blinken added that Washington would continue working for a diplomatic solution to the tensions.