WASHINGTON, July 19 (Reuters) - Belarus opposition leader Sviatlana Tsikhanouskaya appealed for more help from the United States on Monday as she began a visit to Washington with plans to meet top Biden administration officials this week. Belarus President Alexander Lukashenko has kept a tight grip on Belarus since 1994 and has cracked down on street protests that began over a presidential election last August which his opponents say was rigged so that he could retain power. Tsikhanouskaya, 38, was a candidate in the election instead of her husband Sergei Tsikhanouskiy, a video blogger who has been jailed since May 2020 on charges such as violating public order, which he denies. Tsikhanouskaya fled to neighboring Lithuania after Lukashenko"s crackdown. She planned to meet U.S. Secretary of State Antony Blinken later on Monday. A senior administration official said meetings with senior White House officials were planned this week as well. She told CNN that more help is needed from the United States and the European Union. "The USA has a moral obligation to be with us. I ask the USA to help civil society survive," she said. "Stand with Belarus." The senior administration official said the United States "stands with" Tsikhanouskaya and the people of Belarus and "will continue to support their democratic aspirations."