EU leaders will unite in warning Vladimir Putin that there will be “massive consequences and severe cost” if Russia invades Ukraine, a leaked draft has revealed. The message will be sent to the Kremlin via a post-summit communique on Thursday, although EU officials decline to flesh out what measures could be taken. The leaders will urge Russia to “de-escalate tensions caused by the military buildup along its border with Ukraine and aggressive rhetoric”. According to the leaked draft, they will say: “The European Council reiterates its support for Ukraine’s sovereignty and territorial integrity. Any further military aggression against Ukraine will have massive consequences and severe cost in response.” Putin has mobilised as many as 175,000 troops on Ukraine’s northern, eastern, and southern border, with the Kremlin blaming “provocative” Nato drills near the border for making the military buildup necessary. The US president, Joe Biden, spoke to Putin last week and the Russian president suggested a list of binding security guarantees that it wanted from the west. A formal document was sent this week. “A detailed discussion of the issue of security guarantees took place in the light of ongoing attempts by the United States and Nato to change the military-political situation in Europe in their favour,” the Russian foreign ministry said in a statement. The White House said it would share these demands with EU governments. One of them is understood to be that Nato withdraw a 2008 pledge to admit Ukraine and Georgia. In a sign that that request is unlikely to be satisfied, Georgia’s president, Irakli Garibashvili, visited Nato headquarters in Brussels on Wednesday morning to meet the organisation’s secretary general, Jens Stoltenberg. Speaking to the European parliament, the European Commission president, Ursula von der Leyen, said the EU was prepared should Russia escalate the military situation. She said: “We all have seen the reports of Russia’s massive buildup of military along Ukraine’s eastern border, and also the attempt to destabilise Ukraine from within. “I want to reaffirm our unwavering commitment to Ukraine’s sovereignty and territorial integrity, as well as the right of any sovereign state to determine its own future. “Of course, we want to good relations with Russia. But whether this is possible, depends first and foremost, on Russia’s behaviour. At this point in time, Russia’s choosing aggressive posture vis-a-vis its neighbours and, as the European Union and its G7 partners have made very clear, further aggressive acts against Ukraine will have massive costs for Russia. “We are prepared. There’s a whole set of economic sanctions in place, targeting the financial energy sector, dual-use goods and defence. Our response to any further question may take the form of a robust scaling-up and expansion of these existing sanctions. And of course, we are ready to take additional unprecedented measures with serious consequences for Russia.” EU officials and diplomats said they would not disclose what measures would be taken as it could weaken their stance. Western countries have varied economic ties with Russia.