European Council leader sees stability, prosperity

The EU-Ukraine Association Agreement calls for a free trade zone and for Ukraine to adhere to European values such as democracy and human rights. It will allow for the country to participate in common border protection and security processes.

In remarks before the signing, European Council President Herman Van Rompuy also remembered those who died in Ukraine.

"In Kiev and elsewhere, people gave their lives for this closer link to the European Union," he said. "We will not forget this."

Van Rompuy said that closer political and economic ties would bring greater security, stability and prosperity to Ukraine and the two other former Soviet states also each signing an EU Association Agreement on Friday, Georgia and Moldova.

"Our joint goal is your full integration into the market of the European Union," Van Rompuy told those countries' three leaders, adding they must push forward with reforms.

He also expressed the EU's solidarity with the three nations in the face of Ukraine's "very difficult" security situation, and the "uncertainties" looming over Georgia's and Moldova's relationships with Russia.

He stressed that Russia had nothing to fear from those nations' closer ties with Europe, adding the EU would engage with Moscow to work for peace.

Putin -- pragmatic or emotional?

As Ukraine's government works to quell the violence in the east, Poroshenko has said that negotiations with Russian separatists there will continue Friday.

Peace is possible if Putin is in the right mood, he told CNN's Christiane Amanpour in an exclusive interview Thursday.

"Sometimes, the position of Mr. Putin is quite pragmatic, sometimes it is very emotional," Poroshenko said. "I just try to find out the time when he is more pragmatic than emotional."

The talks are intended to end fighting that threatens to escalate into a broader conflict.

"I am optimistic and I'm thinking that within a few weeks, maybe months, we can have a deal to establish peace," Poroshenko said.

Putin has agreed to negotiations that will include an EU representative, Poroshenko said. "We do not expect any immediate negative reaction," he said. "I'm ready to make a peace deal with anybody."

He is also ready to fight if necessary but said, "I hate the idea not to use the last opportunity to bring the peace to the region."

Peace plan

Under his peace plan, he seeks a commitment to negotiations, the release of hostages, a mutual cease-fire and the withdrawal of Russian-backed forces from Ukraine.

"All the troops on Ukrainian territory are Russian, they are Russian citizens," he alleged, adding that separatist leaders were from the Russian secret service. "If that continues, it is a real war."

Poroshenko said that Ukraine had seen 18 soldiers killed and 33 injured in the past week, while the separatists had shown "no negotiation, no sign of compromise."