UNITED NATIONS/WASHINGTON (REUTERS) - UN Secretary-General Antonio Guterres is "deeply concerned" that North Korea has indicated it could resume nuclear and missile tests, a UN spokesman said on Wednesday (Jan 1).

"The Secretary-General very much hopes that the tests will not resume, in line with relevant Security Council resolutions. Non-proliferation remains a fundamental pillar of global nuclear security and must be preserved," spokesman Stephane Dujarric said in a statement.