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Pelosi's possible visit to Taiwan raises concerns China might interfere with airspace, US official says

Washington(CNN) Biden administration officials are concerned that China could seek to declare a no-fly zone over Taiwan ahead of a possible visit by House Speaker Nancy Pelosi as an effort to upend the trip, potentially raising tensions even further in the region, a US official told CNN.

China could also respond by flying fighter jets further into Taiwan's self-declared air defense zone, which could trigger a response from Taiwan and the US, the official added. They did not detail what a possible response would entail.

China has sent warplanes into Taiwan's self-declared air defense zone identification zone many times in recent months, an act which does not violate any international law but which usually results in Taiwan taking precautionary defensive measures, including sometimes scrambling its fighter jets.

Chinese planes have not entered the island's territorial airspace -- the area extending 12 nautical miles from its coastline.

The State Department has called on China to cease its intimidation of Taiwan.

Pelosi has been planning a trip to Taiwan in the coming weeks, according to three sources familiar with the planning process.

While other members of Congress and former US officials have visited Taiwan this year, Pelosi would be the highest-ranking US lawmaker to visit Taiwan in 25 years. Then-Speaker Newt Gingrich traveled there in 1997.

Tensions between Washington and Beijing over the issue of Taiwan have heightened in recent months. The Chinese Communist Party has long claimed democratically ruled Taiwan as part of its territory and has repeatedly vowed to "reunify" with the island of 24 million people -- by force if necessary -- despite having never governed it. The US has committed to providing Taiwan with the means to defend itself, though recent weapons sales to Taiwan have been slow to arrive, which has raised concerns among US lawmakers.

The Chinese embassy in Washington referred CNN to the remarks from the spokesperson for the Ministry of Foreign Affairs stating firm opposition to a possible Pelosi visit when asked to comment on the airspace concerns.

The Financial Times was first to report Pelosi's plans for a visit.

President Joe Biden cited concerns from the US military about Pelosi's possible trip earlier this week.

"I think that the military thinks it's not a good idea right now, but I don't know what the status is," Biden said on Wednesday when asked whether it was a good idea for Pelosi to travel to the self-governing island.

Col. Dave Butler, Joint Chiefs of Staff spokesman, said the military "in general" briefs decisionmakers on military assessments. "We talk about what adversaries may do, discuss logistics and military plans and readiness," Butler said. He declined to say whether or not Chairman of the Joint Chiefs of Staff Gen. Mark Milley spoke with Pelosi about a proposed trip to Taiwan.

Pelosi said it's important to show support for Taiwan on Thursday, but said that she would not be discussing any travel plans, calling to a security issue. Pelosi said she heard "anecdotally" about Biden's comments on her possible visit, but said she had not heard anything from the President directly.

"I think what the President was saying is that maybe the military was afraid of my plane of getting shot down or something like that. I don't know exactly," Pelosi said.

State Department officials also have some concerns, two sources said. State Department spokesperson Ned Price deflected questions about the trip on Thursday, calling it a "hypothetical" at this time.

"I am not going to be offering any advice from the is podium," Price said when asked about the State Department position on her possible visit.

Price reiterated that the Biden administration is still adhering to its one China policy, noting that the US does not have diplomatic relations with Taiwan but has a "robust unofficial" relationship with the island.

Voicing opposition to the possible Pelosi visit, China's foreign ministry spokesperson Zhao Lijian, said Tuesday that it "would seriously violate the one China principle and the stipulations in the three China-US joint communiqués and harm China's sovereignty and territorial integrity."

The spokesperson for Taiwan's official office in DC, Sabina Chang, told CNN that Taiwan has "not received any information about a planned visit to Taiwan by House Speaker Nancy Pelosi."

CORRECTION: This story has been updated to reflect that Chinese planes have entered Taiwan's air defense identification zone but have not violated international law.

CNN's Barbara Starr contributed to this report.