TAIPEI (Reuters) - Taiwan President Tsai Ing-wen said on Sunday her trip to Central American allies and transit stops in the United States had elevated the island’s international profile, as China hit back at U.S. President-elect Donald Trump for his remarks on the “one China” policy.

Taiwan President Tsai Ing-wen leaves a luncheon during a stop-over after her visit to Latin America in Burlingame, California, U.S., January 14, 2017. REUTERS/Stephen Lam

Beijing was also upset that Tsai was allowed to stop over in the United States on the arrival and departure legs of her trip to Central America the past two weekends, which it saw as a potential breach of the “one China” policy.

Under the nearly four-decade old policy, the United States has acknowledged China’s position that there is only one China and Taiwan is part of China. It has formal ties with China rather than the island of Taiwan, which China sees as a breakaway province to be reunified with the mainland one day.

“Our first objective (of this trip), was to consolidate our state friendships and allow Taiwan to walk on the international stage,” Tsai said at Taiwan’s international airport upon arrival on Sunday night.

She said she had bilateral talks with four heads of state in Central America. “We also grasped the opportunity during our short transit time in the United States to visit industries and talk with important people in America,” Tsai said.

U.S. officials had said Tsai’s transit stops were based on long-standing U.S. practice and Tsai’s office had characterized her meetings on U.S. soil as private and unofficial.

The visit came amidst mounting controversy over Trump’s remarks about Taiwan.

China’s foreign ministry said on Saturday that its “one China” principle was the non-negotiable political basis for China-U.S. relations, and urged “relevant parties” in the United States to recognize the sensitivity of the Taiwan issue.

The comments, posted on the foreign ministry’s website, were a direct response to Trump’s remarks in an interview with the Wall Street Journal in which he suggested he might use the “one China” policy as a bargaining chip with Beijing.

China had already been furious over Trump’s call last December with President Tsai, who was congratulating him on his election. It was the first time a U.S. president or president-elect had spoken to Taiwan’s leader since the “one China” policy was established in 1979.

After attacking China repeatedly during the election campaign, Trump has continued to criticize China in Twitter messages over its alleged currency manipulation, for its military moves in the South China Sea, and for not doing enough to restrain North Korea’s nuclear and missile programs.

On her way to Central America, Tsai met with senior Republican lawmakers in Houston.

During a visit to messaging service Twitter Inc on Saturday in San Francisco, Tsai reactivated an old account and tweeted: “Had a great visit to @Twitter HQ today. Thank you to @vijaya and team for showing us around!”