Congresswoman Jo Ann Davis, a conservative Republican from Virginia, died Saturday after suffering breast cancer for two years, her congressional staff said.

"Davis had been receiving breast cancer treatment at Duke University and just recently had received positive reports on her condition," the statement said. "However, during the last week Davis' health took a turn for the worse."

Davis, 57, was a member of the armed services and foreign affairs committees in the 435-member US House of Representatives.

Jo Ann Davis, who before running for Congress was a real estate agent, was elected to four two-year terms to represent a district in the southeastern corner of Virginia. Davis was the first female Republican elected to the House of Representatives from the Commonwealth. She served on the Armed Services and Foreign Affairs committees. She was diagnosed with breast cancer in 2005 and underwent a partial mastectomy in July 2006.

In a statement issued by the White House, US President George W Bush mourned Davis, whom he remembered as a fiscal conservative and "strong supporter of our men and women in uniform."

“Her determination to fight the disease is an inspiration to all of us," Bush said.