"Whatever the past may be, we have to do a deal to end the fighting in Ukraine and to move back towards normal relations, including ending the sanctions," Brenton said.
Since April 2014, Ukraine's southeast has been a scene of violent armed confrontation between Kiev forces and Donbas independence supporters.
Western countries blamed the escalation of tensions in southeastern Ukraine on Russia, but Moscow denied any involvement in the conflict and urged for the cessation of hostilities.
However, the West went on to impose several rounds of sanctions on Russia, targeting its defense, banking and energy sectors, as well as certain individuals. Moscow made a retaliatory move and banned foodstuffs from the European Union members, the United States and several other nations.
UK Prime Minister David Cameron was invited by Moscow to attend the Victory Day parade in Russia on May 9 that will mark the 70th anniversary of the end of World War II and victory over Nazi Germany, but the British leader declined the invitation.
