SAN FRANCISCO — Samsung Electronics Co. used “monopoly power” to make exorbitant licensing demands of Apple Inc. over two patents the South Korean company accuses the iPhone maker of infringing, a witness told a jury.

Samsung has declared the patents “essential” and is seeking as much as $399 million in royalties from Apple for infringing them, according to court testimony. Apple has argued in court filings that Samsung can’t assert the two patents because it didn’t properly disclose them to the standard-setting institute. Samsung also has accused Apple of infringing three other patents covering smartphone features.

Testimony concluded Friday at the trial. US District Judge Lucy Koh said she aims to have the companies present closing arguments Tuesday. Jury deliberations may begin later.