EU draws red lines round Ukraine

"I will meet with the new American ambassador to the EU later today and I will ask him to send this message to his president," Tusk added.

He spoke alongside Ukrainian president Petro Poroshenko after a summit that underlined EU policy on Ukraine.

He also spoke ahead of a summit between US leader Donald Trump and Russian leader Vladimir Putin in Helsinki next week, which is set to tackle European security.

The Trump-Putin talks overshadowed the EU-Ukraine meeting.

Their pomp is also gearing-up to overshadow a Nato summit in Brussels this week, with Trump and Putin to bring hundreds of aides, security staff, and business chiefs in their delegations, and with Finland saying it would introduce checks on internal EU borders to maintain security due to the sale of the event.

"Russia's image must not only depend on the organisation of football championships … but on what is the reality, the substance of its politics," Tusk said on Monday, referring to Russia's hosting of the World Cup finals and its posturing more broadly speaking.

Naming names

The EU and Ukraine's joint declaration, unusually, listed the names of six Russian political prisoners, including Oleg Sentsov, a Ukrainian film maker who is on hunger strike.

The declaration, issued in the name of the 28 EU states, also "reiterated our strong condemnation of the clear violation of Ukrainian sovereignty and territorial integrity by acts of aggression by the Russian armed forces."

"We continue to condemn the illegal annexation of Crimea and Sevastopol by the Russian Federation … We remain committed to fully implement our respective non-recognition policies," it said.

"The EU recently again renewed its economic sanctions on Russia, the duration of which remains clearly linked to the complete implementation of the Minsk agreements," it added, referring to the so-called Minsk ceasefire pact, which obliges Russia to withdraw forces from east Ukraine.

Rockets and explosions continued to light up the sky in the region in the run-up to Monday's meeting in Brussels and Tuesday's football semi-final in Russia.

The EU statements on Ukraine's territorial integrity have been commonplace since Russia invaded its neighbour in 2014.

The EU and US have also walked in lockstep on non-recognition and on Russia sanctions.

But Trump has thrown US foreign policy into doubt ahead of his Helsinki summit, saying "we're going to have to see" whether he recognises Russia's claim to Crimea, legitimising a Russian war of conquest in Europe.

He has also thrown into doubt the US commitment to Nato, berating allies for not spending enough money on defence before he meets them in Brussels on Wednesday and Thursday.

Poroshenko will be at the Nato event, amid Ukraine's aspirations to join the Western bloc in the long term and amid its appeals for further military assistance.

"We acknowledged the European aspirations of Ukraine and welcomed its European choice," the EU summit declaration said, referring to Ukraine's hope to one day also join the European Union.

"We reaffirmed Ukraine's role as a strategic transit country for gas, ensuring affordable, secure and sustainable supplies to the EU," the declaration added.

Nord Stream 2

The statement on gas recalled German chancellor Angela Merkel's promise that a new Russian-German pipeline, Nord Stream 2, would not halt Russian gas transit to the EU via Ukraine.

Tusk and Poroshenko rubbished the pipeline as a Russian "geopolitical project" designed to help Putin carve up Europe.

"Nord Stream 2 is a mistake and will not best serve European interests. It is against our strategic interests, our security, and also our rules [energy laws]," Tusk said.

He admitted that there was "little news" on EU efforts to oversee the Russian-German project due to "different opinions" among EU states, in a nod to its Austrian, Dutch, French, and German backers, however, and in a sign of the limits of EU solidarity with Ukraine despite the Trump threat.