An American woman's eight-year campaign to renew former president Richard Nixon's gift to China ended Monday as U.S. officials presented the Beijing Zoo with two new woolly ambassadors.

The goodwill couple, Alaskan musk oxen Koyuk and Tanana, were formally given as gifts to China - after enduring two months of quarantine confinement and medical treatment - during a morning ceremony at the capital zoo.The presentation capped a nearly eight-year campaign by Helen Miller, 65, of Moultrie, Ga., that began with the deaths of two earlier musk oxen - Milton and Matilda - given to China by Nixon.

"I had heard that Chinese children were so saddened by their deaths (and) came to the zoo only to find their bridge of friendship with the United States wasn't there any more," she said.

"That bridge is worth repairing," said Miller, who wrote nearly 700 letters and contacted Vice President George Bush and U.S. Ambassador to China Winston Lord during her campaign.

The ceremony also ended a five-year "panda gap" in Sino-American relations during which native American wildlife was not formally represented at the Beijing Zoo. China has been represented during that time by Ling Ling and Xing Xing, the giant pandas at the National Zoo in Washington, D.C.