The offensive is largely the brainchild of US Under Secretary of State for Political Affairs Victoria Nuland.

"The offensive is largely the brainchild of US Under Secretary of State for Political Affairs Victoria Nuland."#Ukraine #UkraineRussiaWar️ https://t.co/EvFu2rxkFk

— ⏳Towhee 🌏☮️ (@amborin) April 13, 2023

From the Asia Times article.

Nuland has a long history with Ukraine. In the Obama administration, she supported the Maidan protestors and the overthrow of the legally elected, but pro-Russia, government of Ukraine.

There are secret recordings of her conversations with the US ambassador to Ukraine at the time, deciding who would be best to replace Viktor Yanukovych, who was then president of Ukraine. Yanukovych was elected in 2010 in a runoff between himself and Prime Minister Yulia Tymoshenko. Yanukovych originally came from Donetsk; he is now in exile in Russia.

The US backed the coup in Ukraine, even though it was illegal and undemocratic. Since then most of the Russian-speaking parts of Ukraine have not participated in Ukrainian elections, including Zelensky’s election in 2019. 

Now, after Russian annexations, participation is foreclosed as the Donbas region “republics” in eastern Ukraine (Donetsk and Luhansk, Kherson, Zaporizhzhia and Crimea now are, in the view of the Russian government, part of Russia.

The planned counteroffensive, despite US and NATO support, faces some significant obstacles. The nine US-NATO-equipped brigades have less armor than promised by NATO.

Here