Ukraine: Opposition Warning For President By Katie Stallard, Sky News Correspondent in Kiev Ukraine's opposition leaders have told President Victor Yanukovich not to bother coming back if he "sells out" to Russia in a meeting with Vladimir Putin on Tuesday. They fear he is preparing to move the country toward a customs union with Moscow, turning his back on the path to European integration, in a return to the sphere of influence of its former Soviet masters in the Kremlin. "He might as well stay in Moscow and not come back to Kiev if a customs union agreement is signed," former economy minister Arseny Yatsenyuk said. He said: "We'll give him a really warm welcome if he sells out Ukraine." "The Kremlin wants to take its revenge on Ukraine, divide the Ukraine and drown it in blood," nationalist leader Oleh Tyahnybok told reporters. We forbid this president to sign anything in Moscow that contradicts the interests of the Ukrainian state. US senators John McCain, left, and Chris Murphy support the pro-Europeans Earlier US Senator John McCain warned Russia against interfering in Ukraine's affairs as he told crowds massed in the capital Kiev that America stood with them. The Republican former presidential candidate met opposition leaders and the daughter of jailed former prime minister, Yulia Tymoshenko, with Democrat Senator Chris Murphy, before declaring their solidarity with protesters. Mr McCain said, via a translator: "We intend to return to Congress and inform our colleagues of our impressions which are that this is a historic change in the history of the Ukraine and we strongly support the kinds of actions being taken including Ukraine being included in a European community." The destiny you seek lies in Europe. Ukraine will make Europe better and Europe will make Ukraine better. To all, Ukrainians, America stands with you. The crowd chanted "Thank you, USA," in response. Hundreds of thousands took to the streets on Sunday in a huge rally dubbed the 'day of dignity', where they demanded the resignation of the government, and European human rights. Supporters of Ukranian President Viktor Yanukovich shout slogans in Kiev The ex-Soviet nation has been at the heart of a diplomatic tug of war between east and west since President Yanukovich's refusal to sign an EU trade deal last month, in favour of closer ties with Russia. The demonstrations began on November 21, but have grown in size and intensity since after unsuccessful attempts by police to clear the protest camp. Minutes before Sunday's rally, EU enlargement commissioner, Stefan Fuele announced on twitter that talks with Kiev had been suspended until they received "a clear commitment" from Yanukovich that Ukraine was serious about the deal. "Ukraine: Words and deeds of President and government regarding #AssocAgreement further and further apart," Mr Fuele said. "EU officials told Ukraine that further discussions required "clear commitment (to) sign (but) Work on hold, had no answer," he explained. Ukraine's prime minister, Mykola Azarov, has reportedly demanded a €20bn (£16.85bn) loan from the European Union to offset losses from Russian trade sanctions he insists would follow an EU deal. The country remains deeply divided, between the European-leaning west,and Russian-speaking east, with workers from the president's industrial heartland staging rival demonstrations in the capital over the weekend. Pro-European activists in Kiev's Independence Square One man admitted to Sky News that he had been paid $40 dollars (£24.50) to protest, but other maintained they were loyal to their president. "If the president made a mistake, that doesn't mean you need to gather in maidan (Independence Square)," pensioner Galina Beresneva said, surrounded by large army tents and a field kitchen set up by pro-government organisers. Dock worker Nikolai, 61, said: "We are here because an effort to destabilise the country has begun. I voted for the president, I'm here to back him. But anti-government protesters insist their president is leading the country in the wrong direction, and believe they are now fighting for the future of Ukraine. "I am here against the criminal authorities, joining Europe is a secondary goal," said Oleksander Vdovin, a 25-year-old engineer, wrapped in Ukrainian flag. They have called another mass rally to coincide with Yanukovich's meeting with Mr Putin on Tuesday.