Vin Diesel, star of US action films, has urged the Russian President to take the challenge, but his spokesperson says he's busy.
A three-year-old girl has been found after surviving 10 nights in the Siberian wilderness after her puppy left her side to fetch help.
An opening in the earth in gas-rich northern Siberia could have been caused by a natural underground explosion
Around 70 Russian aid trucks have now entered Ukraine without permission from Kiev and the previously agreed escort of the Red Cross, Reuters reports.
An unnamed Ukrainian government official told the news agency: "The convoy started to move on its own, without consent from the Ukrainian side and unaccompanied by the Red Cross."
Russian President Vladimir Putin has reportedly been informed of the convoy's progress.
Twenty of the 200 aid trucks from Russia have crossed the Ukraine border, Reuters witnesses say.
The trucks are said to be being accompanied by a small number of pro-Russian rebels.
The first of 200 trucks carrying aid from Russia have driven into Ukraine with the help of the Red Cross, the Associated Press reports.
BREAKING: AP journalist says 1st trucks in Russian aid convoy driven into eastern Ukraine by Red Cross.
Ukraine's armed forces claim to have killed "around 100" rebel fighters near the eastern town of Snizhne.
Defence officials said government forces had also destroyed 11 missile systems and tanks but the claims could not be immediately verified.
While rebels said they had seized two settlements west of Snizhne and captured 13 Ukrainian troops, including three officers.
Russia has said it is "no longer prepared to tolerate" any delays to its aid convoy entering Ukraine.
In a statement the foreign ministry said: "All excuses to delay sending aid have been exhausted. The Russian side has decided to act."
Reuters witnesses reported the trucks are still currently at the border but Russia warned against any attempts to disrupt them coming through.
Russian food safety watchdog ordered the closure of four McDonald's restaurants in Moscow, including the fast food chain's first Russian branch, which is the busiest in the firm's global network.
Russia's food safety watchdog said it was looking at possible breaches of sanitary rules at McDonald's and was starting unscheduled checks in several Russian regions.
But many in Russia say the checks are driven by the deterioration in relations between Russia and the West over Ukraine.
"Obviously, it's driven by the political issues surrounding Ukraine," said Alexis Rodzianko, President and CEO of the American Chamber of Commerce in Russia. Several Western countries, including the US, have imposed economic sanctions on Russia over Ukraine.
Ukrainian President Petro Poroshenko will meet Russia's Vladimir Putin to discuss the crisis in eastern Ukraine. Mr Poroshenko said he would ask for the pro-Russian rebels to be withdrawn from Ukraine, according to the presidential website.
Mr Poroshenko is scheduled to see Mr Putin in the Belarussian capital Minsk on August 26 at a meeting that will also include top leaders of the European Union and of the Russian-led Customs Union.
The International Committee of the Red Cross has sent 35 staff to help smooth the way for a Russian humanitarian convoy, which has arrived at the Ukraine border.
"We are ready to roll with this convoy, there has been a last-minute delay. We are hopeful that it will be resolved shortly," ICRC spokesman Ewan Watson told Reuters.
The first vehicles of the Russian aid convoy were allowed to cross the border between Russia and Ukraine earlier. They are being inspected by Ukrainian officials in a territory beyond the Russian checkpoint.
Russia has ordered the temporary closure of four McDonald's restaurants in Moscow over "sanitary violations".
The move comes amid rising US-Russian tensions over Ukraine.
Earlier this month the Kremlin imposed bans on Western food imports after it was hit by a fresh round of economic sanctions from the US and European Union.
One of the closed restaurants, on Moscow's central Pushkin Square, drew crowds of thousands when it first opened in 1990, becoming a symbol of openness with the West.
Ukrainian border guards have begun checks on a convoy of Russian trucks carrying aid supplies to the east of the country, the border guards service said.
Spokesman Andriy Demchenko told Reuters: "I can confirm that the Ukrainian side began border-customs formalities relating to the Russian humanitarian cargo."
But he said that at this point the cargo was still in Russian territory.