MOSCOW. Russia has begun military exercises, involving more than 8,000 troops, close to the border with Ukraine. The defence ministry in Moscow confirmed that artillery such as rocket launchers and anti-tank weapons would also be involved in the exercises. They come at a time of high tension ahead of Crimea’s referendum on Sunday on whether to join Russia. US Secretary of State John Kerry has warned of a “serious series of steps” against Russia if the vote goes ahead. UK Foreign Secretary William Hague has also called for the referendum to be abandoned, warning that EU sanctions would be stepped up if there is no progress in the “next few days”. Kerry is due to meet his Russian counterpart Sergei Lavrov to discuss the crisis in London on Friday, amid fears that Moscow is attempting to annex the mainly ethnic Russian autonomous region of Crimea. Russian President Vladimir Putin told a meeting of his Security Council that this was an inter-Ukrainian crisis that “arose not through our fault, but we are involved in it, one way or another”. He said he wanted to discuss how to “build relations with our partners and friends in Ukraine and our other partners in Europe and the United States”. In a sign of the tension spreading, Belarus - a Russian ally - has asked Moscow to deploy extra fighter jets and military transport aircraft after Nato boosted its forces in the neighbouring Baltic countries. Bolstering defences Russia confirmed that military exercises had begun in the regions of Rostov, Belgorod and Kursk, which are close to the border of Ukraine, and would continue until the end of March. “The main aim... is a multi-faceted check of the units’ cohesiveness followed by the performance of battle training assignments in unfamiliar terrain and untested firing ranges,” the defence ministry said. Ukraine’s national security chief Andriy Parubiy warned on Wednesday of a “critical situation” on the country’s eastern and southern borders, where he said more than Russian 80,000 troops were now massing. He said there was a “threat of a full-scale invasion from various directions” and warned that some troops were just “two to three hours” from Ukraine’s capital, Kiev. Kerry told Senators that he believed Russia currently did not “have the assets... necessary to be able to march in and take over Ukraine”, though he acknowledged this could change. Speaking ahead of his meeting with Lavrov, he said the question was whether Moscow was “prepared to find a way to negotiate with Ukraine... to resolve this in a way which respects their legitimate interests”. “If there is no sign of any capacity to be able to move forward and resolve this issue, there will be a very serious series of steps on Monday in Europe and here with respect to the options that are available to us,” he warned. EU foreign ministers are expected to discuss possible sanctions when they meet in Brussels on Monday. The European Parliament on Thursday passed a non-binding resolution calling for the EU to consider measures such as an arms embargo and a freeze on the assets of Russians linked to recent events in Ukraine. Earlier, German Chancellor Angela Merkel warned Moscow of “massive” political and economic damage if it did not change course. In some of her strongest language yet on the issue, she told German MPs that Russia had exploited the Ukraine’s vulnerability at a time of great uncertainty and “turned out not to be a partner for stability”. Agencies She said political and diplomatic measures, rather than military action, were the way to resolve the crisis and stressed: “The territorial integrity of Ukraine cannot be called into question.” Meanwhile, the 34-member Organisation for Economic Co-operation and Development (OECD) - which promotes good governance and economic policy initiatives - said it was suspending accession talks with Russia. Both the authorities in Kiev and its Western allies say Russia must pull its troops out of Crimea. They also say they will not recognise Sunday’s referendum, which they say violates Ukraine’s constitution and was hastily arranged with suspected Russian involvement.