Russian President Vladimir Putin has rejected every de-escalation route offered by the US and, on the contrary, has stepped up his military campaign, according to US Secretary of State Antony Blinken on Wednesday.

“We attempted to provide President Putin with possible exit routes. He is the only one who has the authority to decide whether or not to accept them. So far, every time he’s had the chance to do so, he’s pressed the accelerator and continued down the horrifying path he’s been on “Blinken made the remarks during a joint news conference with his British counterpart, Liz Truss.

“Right now, he has a clear plan to brutalize Ukraine, but for what purpose?” Blinken went on to say that Ukrainians have demonstrated that they will not accept any “puppet regime” installed by Putin to replace the elected Ukrainian government.

“If he tries to enforce such a puppet regime by keeping Russian forces in Ukraine, it will be a long, bloody, drawn-out mess,” Blinken said.

Senior U.S. defense officials last month assessed that Russia’s invasion of Ukraine is designed to ‘decapitate’ Ukraine’s government.

More than 2 million people have fled Ukraine since Putin launched the land, sea and air invasion on Feb 24. Moscow calls its action a “special military operation” to disarm its neighbor and dislodge leaders it calls “neo-Nazis.”

The war has swiftly cast Russia into economic isolation as well as drawing almost universal international condemnation. The United States on Tuesday banned imports of Russian oil, while Western companies are rapidly pulling out of the Russian market.

Russian forces hold territory stretching along Ukraine’s northeast border, the east and the southeast. Fighting has taken place in the outskirts of the capital Kyiv, while Ukraine’s second city Kharkiv is under bombardment.

Blinken has also slammed Russia for not allowing safe passage to civilians stuck in cities under heavy bombardment.

“The Kremlin’s proposals to create humanitarian corridors leading into Russia and Belarus are absurd,” he said.

Russia earlier this week had offered Ukrainians escape routes to Russia and its close ally Belarus, a proposal that a spokesperson for Ukrainian President Volodymyr Zelenskiy said was “completely immoral.”