A probable arms sale by the United States to Taiwan will damage relations with China and trigger a strong reaction from Beijing, analysts say.

The Washington Times reported over the weekend that this week the Obama administration was expected to formally notify Congress of a US$4.2-billion arms deal to Taiwan. The deal will include an upgrade for Taiwan's aging fleet of F-16 fighter jets.

China Daily reported that Taiwan applied to buy 66 F-16 C/D fighters in 2007, which have better radar and more powerful weapons than the 146 F-16 A/B fighters it currently has.

Despite requests from Taipei and US Congress, President Barack Obama had reportedly decided against selling Taiwan the advanced F-16 model and the C/D fighters. However, he may authorize the sale of upgrade kits for the F-16 A/B model.

China has already warned of severe consequences if the arms package goes ahead, China Daily said.

Chinese Foreign Ministry spokeswoman Jiang Yu Friday urged the U.S. to abide by the three joint communiqués on relations in which the U.S. pledged to reduce arms sales to Taiwan.

During his visit to Washington, Vice Chairman of China's top legislature Zhou Tienong said Saturday that an arms sale to Taiwan will hurt not only Sino-US relations and cross-Straits ties but also the interests of the American people.

"I certainly expect that we will see reaction from China and we will see suspension of some military exchanges," Bonnie Glaser, China security expert with the Center for Strategic and International Studies (CSIS), said.

But neither Washington nor Beijing wanted to see it escalate, she said during a discussion at the U.S.-China Policy Foundation last week, according to China Daily.

Tao Wenzhao, a senior researcher at Tsinghua University, said that any arms sale that occurred 32 years after the normalization of China-US relations "is incompatible with the big picture".

"The (arms sale) hurts China's core interests. And to keep on doing the wrong thing for 30 years just doesn't make it right," he added.

The arms package is also incompatible with the peaceful cross-Straits situation, Tao said.

Cross-Straits relations have stabilized since incumbent island leader Ma Ying-jeou of the Kuomintang took office in 2008. Ma has been pursuing close economic ties with the mainland.

"The US said it supports peace and stability in cross-Straits relations there is no need to sell more arms to Taiwan," Tao added.

The upcoming leadership election in Taiwan is becoming another factor that might affect Sino-US relations.

"The position of the Taiwan leader who wins the 2012 election is key to the solution of the Taiwan question," said Xin Qi, vice-president of the China Association of Cultural Development, a non-profit civic group that promotes reunification.

There were reports that Washington was concerned about the inability of Tsai Ing-wen to sustain the cross-Straits relationship.

Tsai, the leader of the opposition Democratic Progressive Party (DPP), visited Washington last week to seek support for her "presidential" campaign against Ma.

Richard Bush, director for Northeast Asian Policy Studies with the Brookings Institution, said: "We were very anxious about the situation during 1995 to 2008 (when the DPP was the ruling party and pushed for Taiwan's 'independence'). We have welcomed what has happened since Ma took office."

"The improvement of cross-Straits relations is in the interest of all three sides," said Robert Sutter, professor of international affairs at George Washington University.

"The idea of going back to that (the turbulent situation under former Taiwan leader Chen Shui-bian's leadership) is not possible, given the negative experiences all three sides had in that period."

US arms sales to Taiwan have long been a source of tension in cross-Straits and China-U.S. relations. Last January, China broke off military ties in protest against a US$6.4 billion US arms sale to Taiwan which included Patriot missiles, Black Hawk helicopters and equipment for Taiwan's existing F-16 fleet. In June 2010, China rejected a proposal for a visit by US Defense Secretary Robert Gates. The military exchanges between two countries resumed at the end of 2010.