SINGAPORE, June 3 (Reuters) - Ukraine's plans for a counteroffensive against Russian occupation remain on track, its deputy defence minister told Reuters on Saturday, despite an "unprecedented" wave of missile and drone attacks across the country in recent weeks. He dismissed a proposal by Indonesia's defence minister at the Singapore meetings to establish a demilitarised zone to halt the fighting in Ukraine, saying: "We are not going to negotiate any deal related to loss of our territory, including Crimea. Ukraine has had good meetings and discussions with many countries, including Asian nations, at the Shangri-La Dialogue, Havrylov said