Taiwan and its supporters in Congress are pressuring the Obama administration to sell new F-16 fighter jets to the island, with one senator vowing to hold up the confirmation of a new deputy secretary of state if there is no progress on the issue.

A coalition in Congress that is pushing for the deal has prompted a diplomatic counteroffensive from Chinese officials, who have visited senators, officials, former officials and think-tank analysts to signal their displeasure.

The activity has the State Department looking for a way to deal with the pro-Taiwan contingent without angering the Chinese. The last time the United States sold arms to Taiwan — a $6.4 billion deal last year for Patriot antimissile systems, helicopters, mine-sweeping ships and communications equipment — China broke off all military ties with the United States.

The current debate involves two proposals. One seeks to upgrade 145 older-model F-16s owned by the Taiwanese air force; the other would involve selling 66 newer and more-advanced F-16s to Taiwan.

At play in the decision are the lucrative interests of the defense industry, internal politics in Taiwan — which is scheduled to hold elections next year — and diplomatic relations not only between the United States and China, but also between China and Taiwan.

“The deal is important because when we sell weapons to Taiwan, it emboldens Taiwan to the point where it is able to engage with China from a position of strength,” said Rupert Hammond-Chambers, president of the U.S.-Taiwan Business Council.

Of the two proposals, the sale of the newer F-16s, estimated to be worth $8.7 billion, would anger Chinese officials the most. China claims Taiwan as part of its territory and has viewed U.S. support of the island’s military as an intrusion into its internal affairs.

Chinese Embassy spokesman Wang Baodong warned this week that U.S. arms sales to Taiwan would present challenges to Washington’s relations with Beijing. The United States should refrain from such a sale, he said, “so that the positive momentum of peaceful development across the Taiwan Straits and that of the sound growth of China-U.S. relations is undisturbed.”

The United States is legally obligated to provide weapons for Taiwan’s defense, under the 1979 Taiwan Relations Act, and the island’s supporters in Congress say the new F-16s are needed to keep Taiwanese air power relevant.

“Taiwan desperately needs new tactical fighter aircraft,” said a letter signed by 47 senators that was sent to the White House in recent weeks.

Roughly 70 percent of the island’s fighter jet force will be retired in the next decade, the letter notes. And because F-16s are no longer commissioned by the U.S. Air Force and are produced only for export, its manufacturer, Lockheed Martin, says it will probably shut down its production line in the next few years if no new orders, such as the proposed Taiwan sale, are submitted.

Sen. John Cornyn (R-Tex.), who represents a state where F-16s are assembled, has been the most outspoken on the issue and is holding up a full Senate vote on the confirmation of William J. Burns as deputy secretary of state until Secretary of State Hillary Rodham Clinton moves forward on the fighter jet issue.

An amendment Cornyn introduced last year requires the State Department to produce a report that would assess whether Taiwan’s air force needs the jets.

In a speech last week at the Heritage Foundation, Cornyn said he is negotiating with Clinton to have that report released in exchange for the confirmation vote. A State Department spokeswoman said that no decisions have been made on potential arms sales to Taiwan and that the department does not comment on such matters.

Asia expert Robert Sutter notes that despite Taiwan’s clamoring for fighter jets, the island has not given top priority to shoring up its defense capabilities.

“Their main concern has been its dealings with China, particularly as it becomes more economically tied to China,” said Sutter, an international affairs professor at George Washington University. “At some point, if they’re not doing much in their own defense, you have to ask: Are they free-riding it or maybe cheap-riding it? They aren’t usually punished by China in the aftermath of these arms sales. It’s the U.S. that suffers diplomatically.”