London-based Volodymyr Khandogiy said Ukraine's record on democracy and justice – the former prime minister and joint leader of the Orange Revolution Yulia Tymoshenko has been jailed for seven years in what her supporters believe is an attempt by the president Viktor Yanukovych to keep a political rival at bay – was being addressed.
But he said it should not hinder trade with Northern Ireland.
"There is a question of the democratic standards but I don't believe that this is something that is standing in the way of doing business in the Ukraine," Mr Khandogiy said.
"It's an issue and needs to be addressed and we do address the issues of developing democratic standards by co-operating in those areas with the Council of Europe, with the EU and European Parliament –they are all very keen on those issues.
"But for business, I mean there is a separate track. Overall the situation is very important for political stability. Despite all the difficulties the Ukraine experiences, the trade is developing."
He said trade between the UK and Ukraine had increased by 6% in 2012 and 20% in 2011.
A trade association agreement with the EU is already initialled and ready to be signed at a summit in November. That includes political elements, such as reform of its judicial system, as well as measures to make trade flow between Ukraine and member states.
Mr Khandogiy said the release of Tymoshenko was not a pre-condition of having the trade association signed – but he said Europeans had welcomed the pardon of her allies, Yuri Lutsenko and Heorhiy Filipchuk, who were serving sentences for abuse of office.
The EU has accused Ukraine of applying justice "selectively under political motivation". But the ambassador said: "The UK minister for Europe, David Liddington, made a statement saying it [the pardon] was a step in the right direction and he welcomed the development.
"So it's a complicated issue. If there is to be a court decision you cannot pick up the phone saying she's free, let her go – it must go through the normal judicial process. But this judicial system is not perfect, of course. But it cannot be changed overnight."
He said the UK had been "very straightforward" in its support of membership by Ukraine of the EU.
And the economic turmoil of the EU, particularly the eurozone, had not dimmed Ukraine's EU ambitions.
"Financial troubles, they come and go, but membership in the EU is not only about economy and financials but the civilisational choice of the country, and which civilisation you want to live with," Mr Khandogiy added.