Heads of states of the Customs Union and Ukraine met here Tuesday to discuss the Ukraine crisis and economic cooperation.
Russian President Vladimir Putin said the ongoing conflict in southeastern Ukraine cannot be solved by further escalation of the military scenario.
Noting that Kiev is ready to discuss "various options" to settle the crisis peacefully, Ukrainian President Petro Poroshenko invited the leaders to accept the peace plan he formulated in June.
"I am convinced that this plan remains relevant and the only possible instrument to stop bloodshed and ensure Donbas's post-conflict reconstruction," Poroshenko told the summit, which was also attended by representatives from the European Union (EU).
Donbas is the local name given to eastern Ukraine, which has been the scene of a five-month-old conflict.
Before the start of the summit, Putin and Poroshenko greeted each other with a handshake.
Belarusian President Alexander Lukashenko, in a separate meeting with EU foreign policy chief Catherine Ashton, said the meeting might not produce a major breakthrough over the Ukraine crisis.
"But we need a conceptual decision, in order to start moving toward peace," Itar-Tass news agency quoted him as saying.
Kazakh President Nursultan Nazarbayev, for his part, said the sides should hold meetings regularly, and offered to host the next meeting in his country.
On economic ties, Putin said it will be practical to enhance cooperation between the Customs Union and Ukraine, but that is unlikely to happen if Kiev materializes the Association Agreement with the EU.
"I'd like to say that we are not going to discriminate against anybody ... We will just have to introduce the standard trade regime for Ukraine, the same as the one that is applied between Russia and the EU," said Putin, referring to the possible cancellation of preferential policies for imports from Ukraine.