China's leadership has hit back at U.S. President Barack Obama who condemned the country for constructing an artificial island in the disputed South China Sea. Only yesterday, Obama claimed Beijing was 'using its sheer size and muscle to force countries into subordinate positions' amid reports of controversial land reclamation efforts. But a furious Chinese leadership has argued that it is Washington which possesses - and wields - the greatest military muscle. The war of words come as newly-released satellite images reveal a flotilla of Chinese vessels dredging sand onto artificially-built land masses near the Spratly Islands - an area which many other nations claim. War of words: China has criticised the United States over accusations it is bullying neighbouring countries by building artificial islands (pictured) on the so-called Mischief Reef in the disputed South China Sea . Untouched: Images from before China began its construction there (pictured in 2012) show no signs of tampering . Disputed: But newer images (pictured in March) show Chinese vessels dredging sand onto artificially-built land masses near the Spratly Islands . Territory: The area near the Spratly Islands where China is constructing artificial islands is claimed by many other countries in the region . Agressor: After the American president condemned China for building land masses on disputed territory, its furious leadership claimed it was Washington which possesses - and wields - the greatest military muscle . A Chinese foreign ministry spokeswoman said: 'The US leader talked about China's 'sheer size and muscle', but one can also see clearly who has the biggest size and muscle in the world. Only hours before Obama's comments, Hua Chunying added that China has 'indisputable rights' to the Spratly islands and it was 'protecting its nation's sovereignty', according to the BBC. She said the construction was to serve troops protecting the area, civilian activity such as search and rescue operations, scientific research and commercial fishing. 'The structures... do not affect, nor are they targeted at, any particular country,' she claimed before adding China would 'continue to strengthen' its activities in the area. The US-based Center for Strategic and International Studies (CSIS) has has been picturing and documenting the construction of an artificial island known as Mischief Reef in the South China Sea. Massive expanses of sand and concrete were being unloaded among the Spratly Islands in the disputed waters. China used dredging vessels to dig up sediment from the sea before dumping it on submerged coral reefs to make islands, Ethan Rosen, a geopolitical researcher in China claimed. Before-and-after images from the area show aircraft runways appearing from jungle, solid masses where there was once coral and man-made harbours replacing natural reefs. The country claims the work is necessary to safeguard its sovereignty which it asserts over most of the South China sea. But the Philippines, Vietnam, Malaysia, Brunei and Taiwan all have overlapping claims to the region. Construction: The US Navy initially claimed China was creating a 'great wall of sand' (pictured in February 2014) in the South China Sea . Controversial: A spokesperson from China's foreign ministry said the country 'indisputable rights' to the Spratly islands and it was protecting its nation's sovereignty . They claim China is illegally reclaiming the contested area and creating artificial islands with facilities that could have military use. Late last month, the U.S. Navy reported the latest land mass China had built was 1.5 square miles in size and created by dumping sand on live coral reefs, possibly damaging local ecosystems. It was just one of several artificial islands China had been creating in the region and their exact purpose remains unknown. Analysts claim the images circulated by CSIS reveal that China is trying to create 'facts in the water' to bolster its territorial claim. Manila - one of the most vocal critics of Beijing's actions in the region - has appealed to the international community to intervene after conceding it and other countries in the region are powerless to stop China's controversial construction. Its foreign affairs spokesman Charles Jose said: 'We are asking the international community to tell China that what it is doing is wrong, and to ask China to stop this reclamation work. China's declared defence budget of around £97billion this year is 55 times that of the Philippines' £1.7 billion. Jose believes Beijing is rushing the construction to undermine an upcoming United Nations ruling on the Philippines' claim to the territory. He said: 'We think China has a plan and they think they have the means to do it and they can actually do it. Aerial photo shows Thitu Island, part of the disputed Spartly group of islands in the South China Sea located off the coast of western Philippines, pictured on July 20, 2011 . On Thursday, Obama waded into the debate by telling a town hall meeting in Jamaica that Beijing should not push around countries with which it is in dispute in the South China Sea. The president said: 'Just because the Philippines or Vietnam are not as large as China doesn't mean that they can just be elbowed aside.' The United States broadly supports its Asian allies against Chinese pressure and has asserted that freedom of navigation is in the country's national interest. On Friday, Hua maintained that China has maintained 'security and peace' in the region and was working with neighbouring countries. The commander of the U.S. Pacific Fleet warned  the constructions were 'increasing regional tensions and the potential for miscalculation' late last month. Admiral Harry Harris Jr added: 'China is building artificial land by pumping sand on to live coral reefs - some of them submerged - and paving over them with concrete.' Harris said the region is known for its beautiful natural islands but 'China is creating a great wall of sand with dredges and bulldozers over the course of months'. The dispute centres around hundreds of tiny shoals, reefs and islets in the South China Sea known as the Spratlys and the Paracels. Several south Asian countries stake claim to the territory, though China tries to control the largest portion of the archipelago. Beijing has claimed its right to the collection of land masses is 2,000 years old which, they say, includes the islands in Chinese history. Taiwan supports its claim, and has its own airfield on the island of Taiping. Vietnamese officials say their government has ruled over the land since the 17th century whilst the Philippines, the closest geographically, says the islands belong to them. In 1974, Chinese forces seized the Paracels from Vietnam, killing 70 troops. There were further clashes between the two countries in 1988, with 60 Vietnamese soldiers killed. In 2012 China and the Philippines were embroiled in a lengthy maritime standoff over a Scarborough Shoal. The Filipino military employed its largest warship for the dispute over the stretch of water which they call Panatag. Upon boarding a Chinese military vessel for inspection, officials claimed they found live sharks, clams and illegal reef. Later, Vietnamese border agencies refused to stamp passports asserting Chinese sovereignty over a handful of the islands and in January it was claimed China would be taken to a UN tribunal to challenge its stake.
U.S. President implied that China was bullying its neighbouring countries .
America criticised China for building artificial islands in South China Sea .
Chinese leadership claim Washington wields the greatest 'military muscle'
Nearby countries say China could use the land mass for military purposes .