Riga - German Chancellor Angela Merkel told the EU's eastern partners on Thursday not to expect too much of the bloc and warned Russia to mend its ways over Ukraine if it wanted to rejoin the G7 club of top nations.At the same time, Merkel, who has played a key role in Ukraine peace efforts, said Russia had no reason to fear closer ties between the 28-nation bloc and six of its Soviet-era satellites."The Eastern Partnership is not aimed against anyone, especially not against Russia," Merkel told the German parliament before leaving for the two-day summit in the Latvian capital Riga.At the talks, EU leaders will reaffirm their commitment to developing political and economic ties with Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine, according to a draft communiqué seen by AFP.They aim to build on the November 2013 Vilnius summit that ended in chaos when Ukraine's then president, the pro-Russian Viktor Yanukovych, baulked at signing an EU association accord alongside Georgia and Moldova.His refusal sparked massive pro-EU protests that led to his ouster in February 2014, then to Russia's annexation of Crimea and a bloody conflict in eastern Ukraine with pro-Moscow rebels.Ukraine's pro-Western President Petro Poroshenko completed the agreement last year and wants ultimately to join the EU, but all the signs are that this can only be a very long-term objective at best.The Eastern Partnership is "not an instrument" of EU enlargement, Merkel said. "We must not therefore arouse false expectations which we cannot later fullfil."EU trims partnership ambitionsThe Ukraine crisis has, however, revealed deep differences within the bloc over how to deal with Russia.EU foreign affairs head Federica Mogherini believes it has to find a modus vivendi with Moscow, while some member states such as Britain warn against showing any weakness, especially when it comes to easing sanctions against Russia.The EU said in March it would adjust policy towards its neighbours to take into account their specific circumstances and, crucially, their links - past and present - with other countries.Merkel also warned Russia it could not think about returning to the Group of Seven major industrialised nations as long as it flouted international law in Ukraine - symbolised by the annexation of Crimea.Russia's membership made the G7 the G8 but its partners suspended it last year, refusing to attend a summit in Sochi hosted by Russian President Vladimir Putin in protest at Moscow's support for the rebels in Ukraine.The draft declaration condemns the Crimea annexation outright, causing problems for Armenia and Belarus who have lost some of their early enthusiasm for the EU and have joined the Eurasian Economic Union promoted by Putin."Armenia and Belarus' behaviour is logical: these two countries voted at the UN with Russia against the resolution condemning the annexation of Crimea. They are keeping their line and we keep ours," one diplomatic source said.EU partnership benefitsUnder their EU Association Agreements, Georgia, Moldova and Ukraine commit to political and civil society reforms intended to modernise their economies and establish democratic norms.In return, they can expect greater access to the EU economy, one of the world's biggest markets, and increased political cooperation.Moldova has won a visa-free accord with the EU, but the bloc says Ukraine and Georgia still have work to do to come up to standard even if they have made considerable progress.The two countries are pressing Brussels hard, with Georgia's experience of a brief war with Russia in 2008 and Moscow's backing of the Abkhazia and South Ossetia breakaway provinces a constant source of concern.The summit is also looking set to touch on domestic issues within the EU.With a host of bloc leaders in attendance, newly re-elected British Prime Minister David Cameron will take his case for re-negotiating his country's EU membership terms before an "in-out" referendum promised by 2017."Today I will start discussions in earnest with fellow leaders on reforming the EU and renegotiating the UK's relationship with it," Cameron said in comments released ahead of his arrival in Riga Friday.Meanwhile Greek Prime Minister Alexis Tsipras held debt talks with the leaders of France and Germany ahead of the summit, but gave no sign of a breakthrough ahead of a crucial June deadline.Merkel, French President Francois Hollande and Tsipras "focused on the desire to reach an agreement on the current programme" to support Greece's finances, an aide to the French leader said.