A Downing Street Spokesperson said:
“Yesterday evening, the Prime Minister held a telephone call with President Petro Poroshenko of Ukraine.
“The two leaders discussed the Minsk process and the situation in eastern Ukraine and the need to tackle instability there.
“The Prime Minister reiterated the UK’s strong support for Ukraine, including our commitment to maintaining pressure on Russia through EU sanctions.
“She went on to discuss how the international response to the poisoning incident in Salisbury had shown that coordinated action by a broad range of allies is the most effective way to respond to Russian aggression.
“They also discussed the announcement by the Joint Investigation Team that the missile which brought down flight MH17 belonged to the Russian army – pointing out that such actions fit into a well-established pattern of Russian aggression.
“The Prime Minister offered the UK’s full support to the investigation team which is looking into the incident, which saw 10 UK citizens lose their lives.
“The Prime Minister and President discussed the importance of Ukraine’s reform agenda, and looked forward to the forthcoming Ukraine reform conference in Copenhagen and the opportunity to demonstrate the progress made.
“The Prime Minister also thanked President Poroshenko for the strong cooperation between Ukraine and the UK ahead of the Champions League Final on Saturday, where 30,000 British fans are expected to travel to Kyiv to see Liverpool take on Real Madrid.”