Ukraine announced Friday that it has closed off its eastern border with Russia, signaling the country's first major step toward achieving peace in eastern provinces that have been wracked with violence for more than two months.

Speaker Oleksandr Turchynov, citing Ukraine's Defense Ministry, told Ukraine's parliament Friday that a six-mile buffer zone was created between Ukraine and Russia's border, CNN reports. The announcement came a day after NATO chief Anders Fogh Rasmussen said NATO saw a new "Russian military buildup" near the Ukraine border.

Russia has had chilly relations with Ukraine ever since Russia annexed the Crimean Peninsula in March then amassed troops along Russia's border with Ukraine.

The Ukrainian government has accused Russia of sending in volunteer fighters and military equipment to aid the pro-Russia militants who have led rebellions in eastern Ukraine's Donetsk and Luhansk provinces.

The closure of the border comes after Ukrainian President Petro Poroshenko announced his plan to facilitate a unilateral cease-fire to stop the fighting it the east.

Poroshenko spoke with Russian President Vladimir Putin about the plan Thursday. Putin reportedly supports easing tensions by implementing a cease-fire and ultimately a peace plan.

In the conversation, Poroshenko stressed that Ukrainian hostages must be released, and that security controls must be established on the Russian border.

The first proposed step of the cease-fire was closing off the border, which is now complete. The second part of the proposal includes changing the constitution to decentralize Kiev's power, giving more autonomy to the eastern regions.

The cease-fire plan offers amnesty to rebels who lay down their arms and did not commit serious crimes. He also said that an escape route will be offered to those who disarm so they can leave Ukraine.

"We expect that hostages and seized premises will be liberated. We expect that a large number of civilians will use the security guarantees for the citizens of Donbas," Poroshenko said, referring to Ukraine's eastern region.

Poroshenko also met with official representatives from Luhansk and Donetsk Thursday, and discussed ways in which the government's power can be decentralized and how the ailing economy can be revived.

Meanwhile, the fighting rages on in the besieged east. Separatists raided a military base in the town of Artemovsk Thursday night, seriously wounding one soldier.

As of Thursday, there was no word as to whether rebels were killed in the attack.

Ukrainian forces were also under attack early Thursday in Luhansk, according to CNN.

The government claims it killed around 300 insurgents since fighting recommenced Thursday morning, and that seven servicemen were killed.

According to The Washington Post, Ukrainian security officials also said that Ukraine detained 13 Russian citizens among 90 rebels.

Despite the recent gains in Ukrainian security and moves toward peace negotiations, rebels in the east seem unwilling to compromise.

Igor Strelkov, a rebel leader in Slovyansk, went on YouTube to sarcastically talk about Moscow's lack of assistance, and to say that they will not stand down.

"I am grateful to the Russian Federation, which supports us so strongly," he said sarcastically, adding: "And I still hope Moscow has conscience enough to take action."

In a separate YouTube video posted Thursday night, Strelkov's made a desperate appeal to Moscow for help.

"The militia and the People's Republic of Donetsk urge the Russian leadership to provide urgent assistance to New Russia to prevent further genocide of the Russian population," he said.