The two leaders are due to meet later today at a summit in Minsk, capital of Belarus.
The talks are under the auspices of the Moscow-led Eurasian Customs Union, which also includes Belarus and Kazakhstan, but it is still unclear whether Mr Putin and Mr Poroshenko will meet separately. The EU’s foreign policy head Catherine Ashton will also be attending
The pair last met briefly in June at the D-Day commemorations and the talks come hours after Mr Poroshenko dissolved parliament and announced snap elections for 26 October.
The BBC has more here