<div>US President Donald Trump has refused to rule out accepting Russia's annexation of Ukraine's Crimea region when he meets his Kremlin counterpart Vladimir Putin next month.</div>''<div></div>''<div>Trump is due to have his first one-on-one summit with Putin in Helsinki on 16 of next month. Talking to reporters in Washington yesterday, Trump refused to reaffirm the long-standing US opposition to Russia's intervention in Ukraine</div>''<div></div>''<div>Accepting that Crimea is never to return to Ukrainian control, would be a major concession to Russia, which is languishing under tough international trade sanctions over its actions.</div>''<div></div>''<div>Russia seized Crimea in 2014 after sending in troops, taking over key facilities, and staging a referendum deemed illegitimate by at least 100 countries in the United Nations.</div>''<div><br />''</div>