The eldest daughter of slain Kremlin critic Boris Nemtsov has left Russia, slamming the climate of hatred whipped up by pro-Kremlin propaganda in an apparent "farewell letter" published Tuesday.

"Russian propaganda kills," Zhanna Nemtsova, a 31-year-old journalist, wrote in a column published by Russia's liberal business daily Vedomosti.

Increasingly isolated by the West, Vladimir Putin will hope to find a friendly ear in Pope Francis at their meeting Wednesday, but experts say the Russian President may have misjudged the mood.

The conflicts in the Ukraine and Syria are likely to dominate the talks, organized on the sidelines of a visit to Milan 2015 expo's Russian pavilion.

World leaders Monday warned Russia it would face stepped-up sanctions for its "aggression" in Ukraine, as they wrapped up a G7 meeting also pledging strong action to fight climate change.

At a luxury retreat nestled in the picture-perfect Bavarian Alps, the leaders of the most powerful countries also tackled threats to global security posed by Islamist extremism and risks to the world economy from Greece.

The leaders of Germany and the United States hammered home a tough line on Russia Sunday at the start of a G7 summit dominated by crises in Ukraine and Greece.

German Chancellor Angela Merkel kicked off the day by treating U.S. President Barack Obama to some traditional Bavarian beer garden hospitality, with frothy ale, pretzels and oompah brass music played by locals in lederhosen.

It was once the summer destination for the brightest and best of Soviet children but it slipped into disuse and decay after the Socialist empire crumbled.

Now, however, showpiece holiday camp Artek in Crimea has reopened under Russian control after Moscow grabbed the Black Sea peninsula from Ukraine -- and it is once again aiming to shape a new generation.

Two Russians kidnapped in Sudan's Darfur in January have been freed by their captors, a spokesman for Russia's embassy in Khartoum said Saturday.

The men, Sergei Cherepanov and Mikhail Antyufeev, arrived at Khartoum airport from Zalingei on Saturday afternoon, an AFP correspondent said.

A top Iranian official, in an unusual declaration Saturday, said there remains no trust between Tehran and world powers and either side could yet abandon a nuclear deal after signing.

In comments that laid bare a paradox of long-running negotiations between Iran and the West, Deputy Foreign Minister Abbas Araghchi said an agreement -- due by June 30 -- was nearing despite neither side trusting the other.

Two Russians kidnapped in Sudan's Darfur in January have been freed by their captors, a spokesman for Russia's embassy in Khartoum said on Saturday.

The two men were abducted by an unidentified group near the town of Zalingei, capital of Central Darfur state, on January 29.

The United States is considering a range of moves to counter Russia's alleged violation of a nuclear arms treaty, including bolstering missile defenses or even deploying land-based missiles in Europe, officials said Friday.

The options are expected to be discussed at a meeting of senior military officers and diplomats convened by Defense Secretary Ashton Carter during a visit Friday to Stuttgart, Germany, Pentagon officials told Agence France Presse.

Russia and China on Friday opposed a U.S.-led request to impose sanctions on two Libyans accused of obstructing U.N. talks on forming a national unity government, diplomats said.

Britain, France, Spain and the United States had sought the measures to shore up efforts by U.N. envoy Bernardino Leon to clinch a political deal before the start of Ramadan on June 17.