A Kremlin spokesman confirmed on Friday that Russia has built up its military presence on the Ukrainian border.

"We have troops in different regions, and there are troops close to the Ukrainian border. Some are based there, others have been sent as reinforcements due to the situation in Ukraine," spokesman Dmitry Peskov told Rossiya 1 television.

Ukraine's Prime Minister Arseniy Yatsenyuk on Friday pledged "special status" for the Russian language and a broad decentralization of power in a bid to defuse pro-Moscow protests sweeping the east of the country.

"We will accord special status to the Russian language and guarantee to protect it," Yatsenyuk said.

Russia's education ministry has proposed a new anti-terrorism law calling for continuous monitoring of Internet use in schools and universities, a measure which critics say is aimed stamping out dissent.

According to the text of the bill published Thursday by the Ministry of Education, school and university officials should "analyze the personal sites of students and personnel" and compile reports on those "who have a tendency towards breaking the rules".

Russia will build new military compounds in the next two years on the Kuril islands that are the subject of a territorial row with neighboring Japan, a top commander said Friday.

"The decisions on constructing military base settlements on the islands Iturup and Kunashir have been taken and confirmed," the commander of Russia's Far Eastern military district Sergei Surovikov said, Russian agencies reported.

The four-way agreement on Ukraine thrashed out in Geneva is the first sign of progress between Russia and the West in a months-long standoff, but a litany of problems remain unresolved, analysts said.

Russia is clearly keen to avoid sanctions that could hurt its already fragile economy and President Vladimir Putin is wary of provoking a military conflict with the West or a civil war in Ukraine, they added.

Fugitive U.S. intelligence leaker Edward Snowden on Friday defended his decision to question President Vladimir Putin in a televised phone-in over the extent of Russia's surveillance activities.

Snowden, writing in Britain's Guardian newspaper, said he was taken aback at criticism of his decision to take part in the show during which Putin greeted him, to laughs from the audience, as a fellow "former agent".

Ukraine has accepted the International Criminal Court's jurisdiction to probe crimes committed before and during the fall of ex-president Viktor Yanukovych, the Hague-based ICC said on Thursday.

"Today the registrar received a declaration lodged by Ukraine accepting the ICC's jurisdiction with respect to alleged crimes committed in its territory from November 21, 2013 to February 22, 2014,"

The United States will send helmets, medical supplies and other non-lethal military assistance to Ukraine amid fears of another Russian incursion there, Defense Secretary Chuck Hagel said Thursday.

Hagel said he had informed Kiev that President Barack Obama "has approved additional non-lethal military assistance for health and welfare items and other supplies."

Russia, Ukraine, the U.S. and EU reached a surprise deal Thursday on de-escalating the worsening Ukrainian crisis, in a ray of hope for the former Soviet republic that has plunged into chaos.

The agreement reached in Geneva comes as a strong contrast to earlier hawkish comments made by Russian leader Vladimir Putin, who left the door open for intervention in Ukraine.

Russian President Vladimir Putin exuded self-confidence as he fielded four hours of questions in his traditional phone-in marathon, keeping open Russia's diplomatic and military options on the Ukraine crisis.

Putin basked in the glory of Russia's lightning takeover of Crimea from Ukraine last month, sitting impassively as dozens of locals in the Crimean port of Sevastopol chanted "Thank you!" in a live link-up.