Manila wants a diplomatic solution to the impasse over Huangyan Island, analysts said, as it decided to send an ambassador to China.

Philippine President Benigno Aquino III has designated career diplomat Sonia Brady as the new ambassador to China, deputy presidential spokesperson Abigail Valte said on Saturday, a few days after Aquino approved the appointment of Brady on May 23.

Aquino wanted "someone who is already familiar with the politics and the culture of that country. That person can hit the ground running", Valte said of Brady, who will have to pass the Commission on Appointments prior to taking her position.

The commission refused to approve the posting of Domingo Lee, who is now Aquino's special envoy to China, saying Lee was inexperienced.

It is abnormal for the Philippines to have not appointed an ambassador to China for more than one year, said Ren Yuanzhe, a researcher at China Foreign Affairs University. The situation reflects the strained relationship between Manila and Beijing, and any two countries with normal diplomatic relations should exchange ambassadors based on the principle of reciprocity.

Ambassadors are particularly needed when there are difficulties in mutual ties, he said, hoping the veteran, who served as ambassador in Beijing from 2006 to 2010, could play her due role in connecting the two countries and achieving a smooth and friendly relationship.

The Philippines has gone through two phases over its policy toward China since the Huangyan Island incident, Ren said.

"Currently, Manila not only expresses the willingness (to seek) diplomatic solutions through various channels, but it also hopes to increase its leverage in future negotiations with Beijing by strengthening military relations with Washington."

Tensions in the South China Sea escalated on April 10 when a Philippine warship harassed 12 Chinese fishing vessels that had sailed near the island to seek shelter from inclement weather.

The Philippines has turned to its main defense ally, the United States, for support. Aquino is due to meet with President Barack Obama at the White House in early June.

A repositioning on bilateral military ties would probably be discussed during the meeting, said Ren, including holding more military exercises, increasing military aid to Manila and helping train troops.

But Valte said the visit "is no way in connection with the standoff (with China)".

The White House said Obama will discuss with Aquino the "close strategic, economic and people-to-people ties" and their cooperation in the Asia-Pacific region.

The US has put a renewed focus on Southeast Asia, stepping up ties to the economically dynamic region where several countries have been involved in territorial disputes with a growing China.

However, because the US neutral position over the South China Sea issue is consistent, it is unlikely for the Obama administration to give overt support in response to Manila's request over the South China Sea, Ren added.

Meanwhile, hot on the heels of a promise to supply a number of vessels to the Philippines, Japan is now sending three naval ships to Manila for a four-day port call scheduled to start on Monday.

An editorial in the Japanese newspaper Yomiuri Shimbun said Japan couldn't afford to ignore the dispute over Huangyan Island, as it faces friction with China on the Diaoyu Islands, adding that the Japanese government plans to use official development assistance to provide the Philippines with patrol vessels.

These actions by Japan, which is not relevant to the South China Sea issue, would complicate the issue further, said Ren.