The renewed U.S.-China trade truce struck in London left a key area of export restrictions tied to national security untouched, an unresolved conflict that threatens a more comprehensive deal, two people briefed on detailed outcomes of the talks told Reuters.

The latest US-China trade talks in London yielded limited progress, leaving key export control issues unresolved. While both sides agreed to ease tariffs55% on Chinese goods and 10% on US goodscritical

China has approved "a certain number" of export permits for rare earth elements and related items, its commerce ministry spokesman said on Thursday.