German Chancellor Angela Merkel on Friday (18 July) said Russia must acknowledge its share of responsibility in the Ukraine plane disaster.

"It is important to have an international investigation as soon as possible. There are many indications that the plane was shot down, so we have to take things very seriously," Merkel said in Berlin during her traditional summer press conference.

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A Malaysian Airlines passenger plane flying at high altitude from Amsterdam to Kuala Lumpur crashed on Ukrainian territory on Thursday, killing all 298 people onboard. According to leaked tapes and the US intelligence service, the plane was shot down by a Russian-made missile.

Merkel called on Russia to "acknowledge its responsibility" for what is happening in Ukraine, especially since it allowed weapons and tanks to cross the border into Ukrainian territories controlled by the pro-Russian separatists.

She said she spoke to Russian President Vladimir Putin on Thursday night and that they have "very diverging opinions" about the situation in Ukraine.

EU leaders on Wednesday agreed to widen the sanctions regime to allow companies to be blacklisted. Merkel said "we will continue on this path", especially after the plane crash.

"Those who shot the plane down must be brought to justice, that's why an international inquiry is needed. It's true that separatists are heavily armed and there is evidence that parts of this armament came from Russia. That is why the border regime is so important and for OSCE inspectors to be able to go and see what is coming across the border," Merkel said.

She added that Germany is pushing within the OSCE (a European multilateral body) to widen the mandate, for instance to use surveillance drones over the Russian-Ukrainian border.

"But there was not much progress, and here it is Russia's responsibility to move," Merkel said.

In a sign that the airplane tragedy may speed up a solution to the conflict, Merkel noted that "suddenly the contact group [between rebels and the Ukrainian government] was able to hold a videoconference, even though it would have been better if they had managed earlier."

No French warships?

Asked about the sale of French Mistral warships to Russia, Merkel said the current sanctions regime still allows it.

But she added that "Germany has put on hold the construction of a shooting centre in Russia, given the situation," in reference to an already-finished project which still requires some paperwork in order for the Russian side to use it.

This marks a shift from a month ago, when Merkel backed the Mistral sale, noting that the contract had been signed years ago and that only a further escalation of sanctions could stop it.