Rhode Island’s US senators are asking President Obama to extend a federal policy allowing Liberian refugees to live in the United States. Senators Jack Reed and Sheldon Whitehouse joined 14 other senators Monday in a letter urging Obama to extend the March 31 deadline for Liberians to leave the country. The policy that allows Liberian refugees to live and work in the United States must be periodically renewed. In 2011, Obama granted an 18-month extension. The senators’ letter asked Obama for another two-year extension.