no, that was an agreement between Ukraine & Russia, the US and UK known as the Budapest Memorandum of Security Assurances, signed in 1994.
Link.
They actually had nukes at the breakup of the USSR; the article says they had the world's 3rd largest nuclear arsenal at the time. they gave them up in exchange for the assurance from those three powers that they would respect Ukraine's territory and independence, and not take military action against it.
the article also makes it clear we have no obligations to defend Ukraine:
PIFER: There's a very important reason why it's the Budapest Memorandum of Assurances and not of guarantees. And we were very clear - and the Ukrainians understood this back in 1994 - that we were not going to use the word guarantee because we were not prepared to extend a military commitment.
Russia has violated the terms of the memorandum. We haven't.
shit has gotten much worse for my family there, since Yanukovich was thrown out and Poroshenko was elected president. Inflation is bad, and currency controls make it difficult to withdraw enough cash to buy things. They made these changes to inch closer to Western/EU standards of government and law, but the short term outlook as deteriorated, and this undeclared war and insurgency has only made a bad situation worse, and nearly impossible to see a way out.