Chinese President Xi Jinping says his country will not act aggressively regarding territorial claims in the South China Sea but is determined to safeguard its interests there.
In a speech during a visit to Berlin, President Xi said "on the issue of the South China Sea, we will not provoke trouble ourselves but we will not fear troubles provoked by others either."
"When it comes to our sovereignty and territorial integrity we will strongly safeguard these interests," he said.
China's claims over islands, reefs and atolls in resource-rich waters of the South China Sea have set it directly against Vietnam and the Philippines, while Brunei, Taiwan and Malaysia have claims too.
Manila boosts military aircraft capability
The Philippines has signed agreements to buy $US528 million worth of military aircraft from South Korea and Canada amid ongoing territorial disputes with China.
"After more than four decades of stagnancy in its dream of improving its capability, our air force has found a promise of new life with the realisation of our (military) modernisation programme," Philippine Defence Secretary Voltaire Gazmin said.
Korea Aerospace Industries will deliver 12 FA-50 jets worth $421.12m in just over three years under a contract agreed by Philippine defence officials and South Korean government representatives.
The South East Asian country also completed a $107m contract with Canadian Commercial Corp. and Canada's Bell Helicopters to build eight helicopters for the military.
The twin deals are part of the Philippines' $1.674b effort to upgrade its armed forces, particularly units tasked with patrolling disputed territory in the South China Sea.
These units are dwarfed by those of neighbouring China, which claims most of the area, including waters and islets much closer to the Philippines.
China said its coastguard on March 9 blocked two Philippine-flagged vessels approaching Second Thomas Shoal, which is guarded by a small group of Filipino marines but is also claimed by Beijing, the latest in a string of such confrontations.
Under the military upgrade programme, President Benigno Aquino's government has also acquired two refurbished frigates from the US coastguard.