KIEV, July 1 - President Petro Poroshenko said on Tuesday government forces would renew offensive operations against rebels and "free our lands," hours after a ceasefire to allow for peace talks with pro-Russian separatists had expired, Reuters reported.

Poroshenko, who accuses Russia of fanning violence in eastern Ukraine, dismissed Moscow's offers to defuse the crisis, and blamed the rebels for failing to keep to the truce or follow a peace plan he had outlined. "We will attack and free our lands. The decision not to continue the ceasefire is our answer to terrorists, militants and marauders," he said in a televised statement delivered in front of the blue-and-yellow Ukrainian flag.

The announcement came after a four-way phone call with Russian President Vladimir Putin and German and French leaders aimed at helping end the crisis in Ukraine's Russian-speaking east where government forces have been battling rebels since April.

Poroshenko had extended a government ceasefire last week until 10 p.m. (1900 GMT) on Monday to allow for peace talks with the so-called contact group involving separatist leaders, a former Ukrainian president, a senior representative of the OSCE rights and security body and Moscow's ambassador to Kiev.

"The unique chance to implement the peace plan was not realized. It happened because of the criminal actions of the militants. They publicly declared their unwillingness to support the peace plan as a whole and in particular the ceasefire," Poroshenko said.

Moscow could face more penalties from the European Union on top of existing asset freezes and visa bans unless pro-Russian rebels act to wind down the crisis in the Ukraine's Donetsk and Luhansk provinces.

Before his announcement, Poroshenko had met with security chiefs, some of whom had called against a ceasefire extension because of military losses and fears that the rebels were using it as an opportunity to regroup and rearm.

A statement tweeted by the Foreign Ministry said 27 Ukrainian servicemen had been killed and 69 wounded since the ceasefire began on June 20.

Putin had urged during the telephone call for an extended ceasefire, a Kremlin statement said.

At Putin's request, the Russian parliament last week revoked the right it had granted him in March to invade Ukraine in defense of its Russian-speakers.

EU leaders said on Friday they were ready to meet again at any time to adopt more sanctions on Russia. Diplomats said they could target new people and companies with asset freezes as early as next week. More than 60 names are already on the list.

Although it has drawn up a list of hard-hitting economic sanctions, the EU is still hesitating over deploying them because of fears among some member states of antagonizing Russia, their major energy supplier.

Poroshenko, who had been under Western pressure to extend the ceasefire, faced rising anger at home over the military deaths. Local media said hundreds of people had gathered outside of his administration building in Kiev in anticipation of a statement on the fate of the truce. (rt/ez)