Kim Hjelmgaard and Oren Dorell

USA TODAY

Amid ongoing reports of fighting in its restive eastern regions, Ukraine signed an economic pact with the European Union on Friday despite objections from Russia, which warned that the deal would have grave consequences.

The broad deal signed by Ukrainian President Petro Poroshenko provides closer trade and political ties and allows for free trade within the EU, as well as key business-related reforms for Kiev. Poroshenko hailed the agreement as the "most important day" for his country since it became independent from the Soviet Union.

Poroshenko also extended a cease fire in the nation's east for three days, the Associated Press reported Friday evening.

The economic pact comes months after deadly protests broke out this winter when then-Ukrainian president Viktor Yanukovych — ousted by demonstrators in February — decided not to sign the trade deal under pressure from Moscow.

Georgia and Moldova also signed association agreements with the EU on Friday in a move opposed by Russia. Georgia has already lost chunks of its territory and Black Sea coast to rebels backed by Russia after a brief war with Russia in 2008.

"There will undoubtedly be serious consequences for Ukraine and Moldova's signing," Grigory Karasin, Russia's deputy foreign minister, said Friday.

The EU's deal with Ukraine is especially sensitive, as it comes at a time when a fragile cease-fire between the Ukrainian government and pro-Russia separatists is due to end, and as Europe's top diplomats decide whether to impose fresh economic sanctions on Russia.

EU leaders said they will wait until Monday to decide on any new sanctions, which will be based on whether there is a cease-fire agreement that includes the return of three border checkpoints to Ukrainian government control, the release of European observers by insurgents, and substantial negotiations on implementing Poroshenko's peace plan.

During President Obama's return to Washington on Friday from a visit to Minnesota, his spokesman Josh Earnest told reporters the likelihood of new sanctions on Russia would increase if the E.U. conditions are not met.

"We have signaled a clear willingness to act with partners and allies to further isolate Russia … additional unhelpful action will lead to additional economic costs," Earnest said, adding. "I'm not prepared to draw a clear line between these steps and sanctions at this point."

Russian President Vladimir Putin did not immediately comment on the trade pact but, in recent days, has signaled that he wants to de-escalate the conflict.

"The most important thing is to guarantee a long-term cease-fire as a precondition for meaningful talks between the Kiev authorities and representatives of the southeast (of Ukraine)," he said Friday.

European Council President Herman van Rompuy described the signings as a great day for Europe.

"The EU stands by your side, today more than ever before," he said. "There is nothing in these agreements or in the European Union's approach that might harm Russia in any way."

Dmitry Peskov, a spokesman for Putin, told Russian news agencies that the Kremlin would respond to the EU-Ukraine accord "as soon as negative consequences arise for the economy."

But Peskov dismissed the threat of immediate action against Poroshenko's government. "In order for those (consequences) to arise, the signed agreement needs to be implemented," he said.

Meanwhile, a week-long cease-fire between Ukrainian government forces and pro-Russian separatists fighting in east Ukraine was set to expire at 10 p.m. Friday. Poroshenko indicated that he might extend it, telling reporters at a news conference that a decision would come later Friday, after he consults with government officials.

While some rebel leaders met Friday with negotiators from Ukraine and Russia, Igor Strelkov, the self-styled commander in chief of the so-called Donetsk People's Republic, rejected any extension of the cease-fire.

"We will not comply," Strelkov wrote on his website. "Our conditions remain the same — the withdrawal of troops by 10 km (6 miles) at least, cease shelling, unblocking of railways."

Contributing: Associated Press