Hundreds of pro-Kiev activists from Crimea's Tatar community on Sunday launched a blockade of roads from Ukraine to the peninsula to protest Russia's seizure of their home region. 

Accompanied by members of the Ukrainian ultra-nationalist Pravy Sektor group, protesters from the Muslim Tatar community used concrete blocks to partially seal off the three roads linking mainland Ukraine to Crimea in an attempt to halt the delivery of goods. 

U.S. Secretary of State John Kerry said Saturday that Syrian President Bashar al-Assad must step down, but not necessarily immediately upon reaching a settlement to end the country's civil war.

Speaking after talks in London with British Foreign Secretary Philip Hammond, Kerry said he was prepared to negotiate to achieve a solution but asked whether Assad was.

Ukraine redoubled its efforts Wednesday to see Russia stripped of its veto power on the U.N. Security Council when the global body's General Assembly meets in the coming weeks.

Numerous nations are upset with Russia for being one of the five permanent council members that together with China has blocked a series of U.N. efforts to impose sanctions on Syrian President Bashar Assad's regime.

Russia on Tuesday began hearing a case against two Ukrainians accused of murdering dozens of Russians during the Chechen war in the 1990s as part of a nationalist killing squad.

The powerful Investigative Committee said that the supreme court of Chechnya -- the highest court in the region -- has begun to hear the case against Stanislav Klykh and Mykola Karpyuk, both of whom have been in pre-trial detention for over a year on charges of murder and belonging to a militant organization.

EU member states formally approved on Monday a six-month extension of sanctions against Ukrainian and Russian figures accused of backing pro-Moscow rebels fighting to break away from Kiev.

"The assessment of the situation did not justify a change in the regime of sanctions nor in the list of persons and entities under restrictive measures," the EU's Council of Ministers said in a statement.

Progress has been made on some contentious issues in the peace process, the foreign ministers of Germany, Russia, Ukraine and France said after holding talks in Berlin on Saturday to prepare for a summit in Paris on October 2.

Germany's top diplomat, Frank-Walter Steinmeier, said the meeting had been "less confrontational" than previous ones and that the warring sides were now "very close" to an agreement on withdrawing heavy weapons from the frontline.

Ukrainian Prime Minister Arseniy Yatsenyuk on Saturday urged the West not to lift sanctions on Russia for its role in the Ukraine conflict unless the Minsk peace deal is fully implemented.

His call came ahead of a meeting of the foreign ministers of Germany, Russia, Ukraine and France in Berlin to prepare for a summit to be held in Paris in early October.

Ukraine's security service on Friday said it had foiled a plot to murder the war-torn country's interior minister and several members of parliament.

Interior Minister Arsen Avakov has been an outspoken critic of Russia and faces prosecution in Moscow for his tough approach to pro-Moscow fighters in the east of the ex-Soviet republic.

Canada, India, Singapore and Egypt are "seriously" interested in buying France's two Mistral warships, a senior official has said, after Paris scrapped a deal to sell the vessels to Russia over the Ukraine crisis.

Louis Gautier, an official who advises the prime minister on defense and security matters, also told lawmakers this week that the cost of abandoning the agreement with Russia would be at least 1.1 billion euros ($1.2 billion) if the government did not find another buyer, according to a summary of his comments obtained by AFP Friday.

Ukrainian President Petro Poroshenko accused Russia on Friday of challenging the "entire democratic world" by annexing Crimea and allegedly arming separatist rebels in the east of his ex-Soviet state.

The pro-Western leader also called on Ukraine's Western allies to toughen their trade and other sanctions on the Kremlin and its biggest firms, should Moscow fail to fulfill the terms of a tentative peace deal to the 17-month war.