Vladimir Putin arrived Friday in Crimea to convene a meeting of his Security Council, ratcheting up tensions over the disputed peninsula that Ukraine has warned could precede an invasion by Russia.
The Russian president arrived in the Crimean port city of Sevastopol to speak with Moscow-backed officials in the territory, which Russia seized in 2014 against the opposition of Ukraine, the U.S. and the European Union.
Putin's arrival escalated the worst confrontation between Russia and its neighbor since a 2015 truce eased violence between pro-Russian rebels and Ukraine in that country's easternmost regions. Last week when Putin accused Ukraine of "terror" tactics in Crimea and vowed "very serious" measures in response, Ukrainian President Petro Poroshenko put his military on high alert.
Poroshenko rejected Putin's claims last week that Ukrainian forces killed two Russian servicemen in Crimea earlier this month. On Thursday, the Ukrainian leader said the chance of escalation was "very significant" and added that "we don't rule out a full-scale Russian invasion."
The standoff comes less than a week before Ukraine's anniversary of its independence from the Soviet Union and a month before Russia holds parliamentary elections. Following several weeks of intensifying clashes between Ukrainian troops and separatists, the dispute also complicates Ukraine's efforts to focus on domestic-based policies needed to restart a stalled $17.5 billion Western-led bailout.
Putin has said that plans to resume talks over the 2015 cease-fire pact at next month's Group of 20 summit in China would be pointless.
