ANTALYA, Turkey — President Obama’s arrival in the Philippines on Tuesday morning will kick off five days of presidential diplomacy aimed at bolstering America’s allies in the region against China’s economic and military might.

White House officials said on Monday that Mr. Obama would continue consultations with world leaders about the terror attacks in and around Paris last week, which had already overshadowed the planned economic discussions at the Group of 20 meeting here.

But Mr. Obama is eager to press the case for what his administration calls a “rebalance” in Asia that aims to empower countries in the region to compete with China by developing closer diplomatic ties and pushing for more open trade.

“We’re strengthening relations with our treaty allies. We’re building ties to new partners and strengthening regional institutions,” said Susan E. Rice, the president’s national security adviser.

Interactive Feature | What China Has Been Building in the South China Sea China has been feverishly piling sand onto reefs in the South China Sea for the past year, creating seven new islets in the region. It is straining geopolitical tensions that were already taut.

Central to that effort is the president’s yearslong push for the adoption of the Trans-Pacific Partnership Agreement, a trade pact involving a dozen countries, including the United States. Mr. Obama will arrive in the region with the agreement in hand, though not yet approved by Congress.

In meetings with more than a half-dozen world leaders and in a speech to business executives, Mr. Obama plans to make his case that passage of the pact is critical to the region’s economic health.

“They will celebrate the achievement of that agreement,” said Matthew P. Goodman, a specialist in Asian economics at the Center for Strategic and International Studies in Washington. “Economics is strategy. And if that’s true, then the president is heading out on this whirlwind trip in a very strong position.”

But any celebration of the trade deal — as well as talks with other nations about the possibility of joining the partnership in the future — may be overshadowed by discussions about how to confront China’s activities in the South China Sea.