German Chancellor Angela Merkel said Tuesday that the European Union was not planning new sanctions against Russia over a fresh spike in violence in Ukraine.

Merkel reiterated that EU member states were considering adding pro-Russian separatists to existing sanction lists imposed on Moscow.

Iran and world powers met in Muscat Tuesday amid growing signs that a long-bargained deal on Tehran's nuclear program will not be struck by a November 24 deadline.

The one-day meeting comes after lengthy discussions between U.S. Secretary of State John Kerry and Iran's Foreign Minister Mohammad Javad Zarif broke off in the Gulf sultanate late Monday with no signs of progress.

Russia's deputy foreign minister Sergei Ryabkov said Tuesday he was "reasonably optimistic" world powers can reach a nuclear deal with Iran by a November 24 deadline, despite big gaps remaining.

"We are not working on plan B, that's for sure," he told reporters in Muscat, though he did not rule out an extension. "If by whatever reason, by whatever development, we are not there, I think we will have time on the evening of the 23rd to develop an alternative."

CNN said Monday it was suspending broadcasting in Russia "in light of recent changes in Russian media legislation," which aim to tighten control on independent news media.

A statement from CNN International parent Turner International, which is part of the Time Warner conglomerate, offered no specific timetable, but the Tass news agency reported earlier that broadcasts would cease as of December 31.

U.S. Vice President Joe Biden warned Russia over Ukraine after new columns of tanks, trucks and heavy artillery rumbled towards the pro-Moscow rebel stronghold of Donetsk on Monday.

The West has repeatedly expressed concern at Ukrainian claims that Russian military reinforcements are being sent in, while Moscow denies that it is involved in the fighting in the eastern part of its neighbor.

A Scandinavian airliner carrying 132 passengers nearly crashed earlier this year into a Russian warplane that was flying covertly, a study of Russia-West military incidents said Monday.

Swedish media reported that the two planes came within 90 meters (300 feet) of each other in the air some 50 miles (80 kilometers) southeast of the Swedish city of Malmo on March 3.

U.S. President Barack Obama and his Russian counterpart Vladimir Putin met briefly Monday in Beijing on the sidelines of an Asia-Pacific summit, a senior U.S. official said.

The two leaders, who have been engaged for months in a standoff over the crisis in Ukraine, "only had a brief encounter where they didn't have time to cover issues," the official said on condition of anonymity.

The Netherlands on Monday held a sombre and emotional memorial for the 298 people who died when Malaysia Airlines flight MH17 was shot down over war-torn eastern Ukraine in July.

"What if the holiday had started a day later? What if the plane had been late? What if I wake up and realize it was all just a dream?" Prime Minister Mark Rutte told the memorial ceremony in Amsterdam, attended by 1,600 of the bereaved.

Russian President Vladimir Putin on Monday said that the investigation of the MH17 crash site is stalling due to Kiev's constant shelling of the rebel-controlled area in eastern Ukraine.

Putin told Malaysian Prime Minister Najib Razak that rebels were not hindering access to the site of the Malaysia Airlines crash, in which 298 people died in July when the aircraft came down in an area controlled by pro-Russian separatists.

Russia' central bank announced Monday that it would intervene to support the ruble only if there was a threat to the "financial stability" of the Russian currency, which has lost 10 percent of its value last week.

The Bank of Russia said in a statement it would allow the ruble to evolve freely in the market, and that it would only intervene in the currency exchange "in case a threat appears to financial stability."