Islamabad, April 2 : Pakistan's Chief of Army Staff (COAS) Gen Qamar Bajwa said that Russia's invasion of Ukraine must be "stopped immediately", terming it a great tragedy, Dawn reported. Speaking at the Islamabad Security Dialogue, Gen Bajwa expressed Pakistan's serious concern over the conflict, adding that "despite legitimate security concerns of Russia, its aggression against a smaller country cannot be condoned". "Pakistan has consistently called for an immediate ceasefire and cessation of hostilities. We support immediate dialogue between all sides to find a lasting solution to the conflict," he added. He said the Russian invasion of Ukraine was very unfortunate as thousands of people had been killed, millions made refugees and "half of Ukraine destroyed". The army chief said the conflict gave hope to smaller countries that they could still defend their territory with smaller but agile forces against aggression by a bigger country by carrying out selective modernisation of equipment, the report said. He noted that Pakistan had enjoyed excellent defence and economic relationships with Ukraine since its independence but relations with Russia were "cold" for a long time because of numerous reasons. However, some positive developments in this regard had taken place recently, Dawn news quoted the COAS as saying. Pakistan has sent humanitarian assistance to Ukraine via Pakistan Air Force (PAF) planes and would continue to do, he said. Gen Bajwa warned that the continuation or expansion of the conflict would not serve the interests of any side, least of all the developing countries which would continue to face socio-economic costs of the conflict, which he said could "easily get out of hand". /IANS