LONDON, Aug 2 (Reuters) - Myanmar should return to a democratically elected government, Britain said on Monday, after military ruler Min Aung Hlaing took on the role of prime minister in a caretaker administration six months after the army seized power. "The decision by the military to extend the so-called state of emergency in Myanmar is unjustifiable and a blatant attempt to solidify their undemocratic power grab," foreign minister Dominic Raab wrote on Twitter. "The junta must hand back control to an elected government and respect the democratic will of the people of Myanmar," Raab wrote.