KIEV (Reuters) - Ukrainian President Petro Poroshenko on Thursday said he hoped to complete talks with Western allies on the supply of defensive weapons, as he warned that upcoming Russia-Belarus military exercises could be cover for an invasion of Ukraine.  The creation of new strike groups of Russian troops for an invasion of Ukrainian territory can t be ruled out,  he said in a speech to parliament.  I hope that we will successfully complete negotiations with our Western partners on supplies of defensive weapons,  he said. 