"Ukraine is defending the EU from Russian aggression", and helping its development will weaken Russian President Vladimir Putin, the Hungarian-born philanthropist said in an interview published in German by Austrian newspaper Der Standard on Monday.
He said Ukraine needed €50 billion to get itself back on its feet, and said he was prepared to pump $1 billion (€922 million) into agriculture and infrastructural projects.
Ukraine is at the edge of bankruptcy hit by the triple whammy of the war in its industrial east, a deep economic recession and the record devaluation of its currency. Its public debt is likely to reach 94 percent of its GDP in 2015.
Soros said his investments "should make a profit", which would go to his foundation rather than him personally.
"The West can help Ukraine by making it more attractive to investors by giving them insurance against political risk," he said.
"That could take the form of financing very close to the European interest rates, which are very close to zero."
Ukrainian investment analysts ICU only predict a return to growth in 2017, and a sharp drop in GDP of 7.6 percent this year.
The new Vienna-based Agency for the Modernization of Ukraine (AMU), which is headed by Austria’s former finance minister Michael Spindelegger, has been criticised by Ukrainian politicians as a PR ploy which is designed to restore the reputation of Ukrainian oligarch Dmitry Firtash.