A US judge asked that the chief executives of Apple Inc and Samsung Electronics Co Ltd speak to each other at least once on the phone before a jury begins deliberating next week in the high-stakes patent trial between the two tech companies.

"It's time for peace," US District Judge Lucy Koh said on Wednesday in a San Jose, California, federal court, just miles from Apple's headquarters.

Apple and Samsung are going toe-to-toe in a patents dispute mirroring a struggle for industry supremacy between the rivals that control more than half of worldwide smartphone sales.