HANOI- Prime Minister Shinzo Abe tried to cement ties with key Pacific-Rim countries during his trip through Tuesday, apparently hoping to prompt incoming U.S. President Donald Trump to maintain U.S. commitment to the security and peace of the region amid China's rising assertiveness.

Asian nations are cautiously watching whether Trump, with his "America First" rhetoric, will keep the United States focused on the region by strengthening freedom of navigation operations and sending U.S. warships to contested waters of the South China Sea to counter China's military buildup, analysts said.

During his six-day trip, Abe agreed with Philippines President Rodrigo Duterte, Australian Prime Minister Malcolm Turnbull, Indonesian President Joko "Jokowi" Widodo and Vietnamese Prime Minister Nguyen Xuan Phuc that U.S. commitment is essential for the prosperity, peace and stability of the Asia-Pacific region.

Amid concerns that Trump, taking office Friday, will shift to a more protectionist U.S. trade policy, Abe also confirmed with the leaders the importance of free trade for the growth of the region in the forms of free trade agreements such as the Trans-Pacific Partnership, from which Trump has said the United States will withdraw.

"There is a need to deepen bilateral relationships with Asian countries at a time of uncertainty" with the election of Donald Trump, a senior Japanese diplomat said in explaining Abe's motivation for his first overseas tour of the year.

"If (Trump) sees that the Asia-Pacific region is essential to U.S. development and continues to be an economically attractive region, we hope there will be no change in the United States' Asia rebalancing policy" promoted by outgoing President Barack Obama, the diplomat said.

Tokyo hopes that Washington will keep exerting influence in the region as Japan faces China's rising military presence in the East China Sea, where China claims the Japanese-controlled Senakaku Islands, calling the islets the Diaoyu, the analysts said.

"U.S. presence in the Asia-Pacific region is necessary to counter China's assertiveness in the South and East China seas at a time when there is no reason for Beijing to soften its expansionary ambitions," said Masafumi Iida, senior fellow at the National Institute for Defense Studies, citing China's intention to recover what it calls lost territories such as the Senkakus.

China's only aircraft carrier embarked on what Beijing called a long-range open-sea training exercise, sailing around Taiwan by way of the East China Sea, South China Sea, and Taiwan Strait, in a sign it is seeking access to the western Pacific.

China is also motivated to use its military power to protect and expand its maritime rights in the South China Sea, a busy shipping lane China uses to import oil from the Middle East, Iida said.

China claims most of the South China Sea and has territorial disputes with Brunei, Malaysia, the Philippines and Vietnam.

"The competition between China and the United States in the South China Sea is set to grow -- such a basic picture is unlikely to change even after the inauguration of Trump," Iida said.

Trump has spoken little about the South China Sea issue, focusing on economic ties with China, threatening to label it as a currency manipulator and impose tariffs on Chinese imports.

As for the TPP, which the United States under the Obama administration reached with Japan and 10 other countries, Abe's talks with leaders of the Pacific Rim nations were a last-ditch effort to keep the trade deal alive.

Abe and Obama have been pushing the TPP so that Japan and the United States, the largest economies in the China-excluding bloc, can take the lead in making "fair and transparent" economic rules. The bloc was also envisaged as strengthening security ties to counter China's rising clout.

"Without the TPP, the Asian policy of the United States could lose its initiative, while China may take advantage of the situation and step up its clout in the region," said Sugio Takahashi, senior fellow at the National Institute for Defense Studies. (Kyodo News)