China, which claims Taiwan as its own territory and has repeatedly denounced Lai as a separatist, held exercises around Taiwan on Saturday, the day after he returned, but on a far lower scale than previous war games in April and last August in protest at Taiwan-U.S. engagement.

China has an especially dislike of Lai, the frontrunner in polls ahead of January's presidential election, due to his previous comments about being a "worker for Taiwan independence".

But Lai did not meet any senior U.S. officials or lawmakers during the visit, aside from the head of the unofficial U.S. body that deals with the country's Taiwan ties. In his public events he talked about peace and dialogue, though he also said that Taiwan would not back down in the face of threats.

"The People's Liberation Army could not find an excuse to make a big fuss," said Ma Chen-kun, a Chinese military expert at Taiwan's National Defence University. "These drills were a lot of thunder, but less rain."

There was no live fire component, unlike last August when China fired missiles over Taiwan, the drill lasted only one day, and was not given a name, unlike the April one, though Chinese state media did launch a series of personal attacks on Lai on Saturday, including calling him a "liar".

Taiwan's defence ministry, in its daily report on Chinese movements over the previous 24 hours, said on Monday morning that it had spotted no Chinese military aircraft entering the Taiwan Strait over that period.

Both Taiwan and the United States had sought to keep Lai's U.S. visit low key, officially describing it as stopovers on his way to and from Paraguay and saying it was a decades-long routine for Taiwan presidents to transit in the United States during trips overseas therefore China shouldn't use the visit as a "pretext" for military drills.

'NO SURPRISES'

Lo Chih-cheng, a senior lawmaker for the ruling Democratic Progressive Party, said Lai's trip was also about the broader process of showing him to the United States as a steady and trustworthy leader.

"Maybe you think the transits were a bit boring or simple, but also there were no surprises," Lo said.

An opinion poll published on Monday by the Taiwanese Public Opinion Foundation showed Lai extending his lead and pulling well ahead of his nearest competitor to be Taiwan's next president, the former Taipei mayor Ko Wen-je.

China's reaction could have been muted since the visit came against the backdrop of both Beijing and Washington trying to improve relations, which could include a visit to the United States later in the year by President Xi Jinping for an Asia Pacific summit.

China could also take other, trade-related, steps to punish Taiwan, having previously stopped Taiwanese fruit and fish imports. On Monday, China suspended Taiwanese mango imports citing a pest problem.

But China has its own domestic problems as well, not least economic ones like a property market crisis, and threat of war with Taiwan is not going to help that, said Fan Shih-ping, a professor at National Taiwan Normal University's Graduate Institute of Political Science.

"Noise about achieving unification through force is a negative for Chinese consumers. Who wants to spend if there's going to be a war?" he said.

(Reporting by Ben Blanchard; Editing by Raju Gopalakrishnan)

By Ben Blanchard