Germany said that plans for Chancellor Angela Merkel and Russian President Vladimir Putin to jointly open a new exhibition Friday that includes war booty taken by the Red Army from Germany had been called off. The cancellation of the exhibition\'s inauguration at the Hermitage Museum in St Petersburg, at which Merkel had been due to give an address, comes amid differences between Germany and Russia over art treasures seized during and after World War II. Asked what Merkel would have said in her speech, deputy government spokesman Georg Streiter responded that she may have pointed to the \"view supported by international law\" that the art works should be handed back to Germany. Nearly 70 years after the end of the war, disputes over war booty remain as Germany seeks the return of treasures looted by the victorious Red Army and talks between the two countries on the issue continue. Merkel was in the Russian city Friday for an International Economic Forum as well as bilateral talks and a dinner with Putin, and the exhibition opening was slated for later in the day. Streiter said there was \"no clash\" and the event was struck from the programme \"by mutual agreement\" after Putin announced a scheduling problem. \"President Putin apparently time-wise had no opportunity for an opening event at which there are also speeches,\" Streiter told a regular news briefing. \"This exhibition and its particular background would have required a presentation via an opening speech,\" Streiter said, adding it would not have been \"appropriate\" for an inauguration that raced through the exhibition. In Moscow Putin\'s spokesman denied that he had ever planned to visit the exhibition at the Hermitage. \"The exhibit will indeed open but there have never been any precise plans to visit it,\" Dmitry Peskov told AFP. \"Putin will not go, no, he has never had any plans to.\" The \"Bronze Age of Europe -- Europe Without Borders\" exhibition includes about 600 items brought after the war from Germany to Russia and has been organised through cooperation between German and Russian museums. In the 1950s, after the death of Stalin, the Kremlin authorised the return to Germany of 1.5 million works of art, including the celebrated Pergamon Altar, built in the second century BCE and now one of Berlin\'s top tourist attractions. But further negotiations have proven difficult. Merkel and Putin clashed earlier in the year over a crackdown by Moscow on non-governmental organisations while the European Union and Russia have persistent differences over the slaughter in Syria.