US Secretary of State Rex Tillerson has said it was up to North Korea to decide when it was ready to engage in sincere talks with the US. He made the statement at a news conference in Cairo on Monday. US Vice President Mike Pence said in an interview that Washington and Seoul had agreed on terms for further diplomatic engagement with North Korea, possibly leading to direct talks without pre-conditions. Tillerson said it was too early to judge whether this was the start of a diplomatic process, Reuters reports.