An aide to Ukrainian President Volodymyr Zelensky warned in an op-ed that Russia's war with Ukraine could be a precedent for a global massacre.

The head of the Presidential Office of Ukraine vowed in a New York Times column that they would fight to the last breath to protect their country.

Russian bombs have fallen over the last week. Despite the constant bombardment of Russian fire, we stand firm and united in our determination to defeat the invaders. Let them make a plea for support for a free Ukraine.

In the op-ed, Yermak called on the West to provide more military supplies and equipment and impose harsher sanctions on Russia to help stop the Russian attack on the country.

Ukraine does not want its allies to put boots on the ground. The West needs to back us up in order to defend our families and land.

The United States, United Kingdom, and the European Union have imposed sanctions against Russia since it attacked Ukraine.

We are thankful to our American and European friends for their quick decisions to help us, for their sanctions against the Russian economy, for the armaments and equipment to deter the aggressor, he wrote.

He asked that we stop being told military aid is on the way. Nothing less than our freedom and yours is at stake.

The Biden administration has already ruled out imposing a no-fly zone over Ukraine.

We know that this would be a serious escalation in the war and that it could bring NATO into conflict with Russia.

He called for a complete embargo on Russian oil and all Russian exports to the United States and Europe.

The measures would cost the world economy, but the alternative is worse.

Again, make no mistake: Mr. Putin wants to advance this ideology by going for blood outside of Ukraine. The Kremlin wants to create a new Russian empire.