WASHINGTON (CNN) -- In a move bound to anger China, the United States intends to sell $6.4 billion in arms to Taiwan, the State Department said Friday.

Apache attack helicopters are part of the weapons deal.

State Department deputy spokesman Robert Wood said Congress -- whose approval is needed for the deal to go through -- was notified Friday afternoon. He indicated the administration expects congressional approval quickly.

The package includes a variety of U.S.-made weapons systems, including Patriot III anti-missile missiles, Apache attack helicopters, Harpoon missiles and Javelin anti-tank missiles.

The deal had been in the works for a few months, Wood said, and the decision is "consistent with U.S. policy of providing arms for defense of Taiwan and consistent with the Taiwan Relations Act."

"This arms deal is a key factor in bringing security and stability across the Taiwan Strait," he added. The deal also gives Taiwan upgrades for Taiwan's E-2T aircraft and spare parts for its air force.

U.S. arms sales to Taiwan have always angered China. The latest deal comes at a time when the United States needs China in negotiations over Iran's and North Korea's nuclear programs. But Wood said the U.S. government decision is no surprise to Beijing, as the Chinese were briefed "several" times about the impending deal.

This is the latest chapter in a decades-long uneasy standoff. China claims Taiwan is its own territory and has threatened to invade if Taiwan ever declares independence. The United States has said it will defend Taiwan if China ever attacks.