Russia said on Wednesday it hoped its deployment of missile systems on the Kurile islands would not damage efforts to settle the long-running territorial dispute between Moscow and Tokyo over the islands.

Russian media reported on Tuesday that Bastion and Bal anti-ship missile systems were now in operation on the islands, an archipelago in the Pacific Ocean over which Russia and Japan have staked rival claims for 70 years.

Delicate diplomacy is underway to prepare for a meeting between the Russian and Japanese leaders in December, when both sides say they hope progress can be made towards settling the dispute.

Kremlin spokesman Dmitry Peskov told reporters the Russian defense ministry had grounds for deploying the missile systems, without giving any details.

“But at the same time from our point of view it should not in any way influence the centripetal trend which exists in our bilateral relations with Tokyo,” Peskov said.

He said that trend existed “in terms of the careful preparations for the forthcoming visit of President Putin to Japan and in terms of continuing contacts to develop our bilateral ties, especially in the economic sphere, and negotiations on the peace deal issue.”

After reports of the deployment emerged, Japanese Foreign Minister Fumio Kishida said the government needed time to consider an appropriate response, Kyodo news agency reported.

The Bastion is a mobile defense system armed with two anti-ship missiles with a range of up to 300 km (188 miles). It has also been deployed in Crimea, which Russia annexed from Ukraine in 2014. The Bal anti-ship missile has a similar range.

The dispute over the islands, known as the Kuriles in Russia and the Northern Territories in Japan, has strained relations between the two countries since World War Two when Soviet forces occupied four islands at the southern end of the chain, and Moscow and Tokyo have still not signed a formal peace treaty ending wartime hostilities.

Japanese Prime Minister Shinzo Abe has launched what he has described as a new approach to dealing with Russia over the row and has arranged to meet Putin in his home town of Nagato in southern Japan.

“No matter what the intentions were from the Russian side, this is more bad news for Abe,” said James Brown, an associate professor at Temple University Japan Campus in Tokyo.

“The Kantei (prime minister’s office) will need to work hard to convince the Japanese public of the wisdom of the ‘new approach’.”

(Reporting by Christian Lowe; Editing by Maria Kiselyova and Janet Lawrence)