WASHINGTON, May 14. /TASS/. US Secretary of State Antony Blinken called the current special military operation stage critical for Ukraine and acknowledged that the upcoming months will demand a lot from Ukraine.

"We meet at a critical moment," he said, speaking at the Kiev Polytechnic Institute. According to Blinken, Russia is "ramping up another offensive against Ukraine, at Kharkov and across the east." The secretary of state believes that "the coming weeks and months will demand a great deal of Ukrainians."

"But I have come to Ukraine with a message: you are not alone. The United States has been by your side since day one. We are with you today. And we will stay by your side until Ukraine’s security, its sovereignty, its ability to choose its own path is guaranteed," Blinken said.

The top US diplomat arrived in Ukraine with an unannounced visit on Tuesday. His speech was live streamed by the US Department of State.