The United States is slapping new sanctions on Belarus, as it calls on the government to release political prisoners, AP reported. The United States says the sanctions announced Thursday against four companies are aimed at pressuring Belarus's President Alexander Lukashenko. The U.S. Treasury Department says the companies, Naftan OAO, Grodno Azot OAO, Grodno Khimvolokno JSC and Belshina OAO are owned or controlled by Belneftekhim Concern. The United States had already targeted Belneftekhim, which officials say is controlled by Lukashenko. The United States and European countries have sought to step up pressure on Lukashenko since he was declared the winner of an election in December that was widely criticized by international observers. -- SPA