North Korea says naval blockade would be 'act of war'

North Korea warned Thursday itwould take "merciless self-defensive" measures should the UnitedStates enforce a naval blockade, which Pyongyang sees as "an actof war,"the isolated nation's state media said.

Citing a foreign ministry spokesperson, the North's KCNA newsagency said a naval blockade would be a "wanton violation" ofthe country's sovereignty and dignity,adding thatNorth Korea was a responsible nuclear power.

U.S. President Donald Trump was taking an "extremelydangerous and big step towardthe nuclear war" by seeking such a blockade,it added. It was not immediately clear what U.S. proposal the agency was referring to.

"Should the United States and its followers try to enforcethe naval blockade against our country, we will see it as an act of warand respond with merciless self-defensivecounter-measures, as we have warned repeatedly," the agency said.

U.S. strike would be 'catastrophic'

The Chinese president said Thursday that war must not be allowed to break out on the Korean peninsula.

President XiJinpingmade thecomments to visiting South Korean President MoonJae-injust days after U.S. Secretary of StateRexTillersonoffered to begin direct talks with North Korea withoutpre-conditions.

But the White House said on Wednesday that no negotiationscould be held until North Korea improved its behaviour.

The White House has declined to say whether President Donald Trump,who has taken a tougher rhetorical line toward NorthKorea,approved Tillerson's overture.

Russian President Vladimir Putin, speaking in his annual end-of-year address Thursday, said Tillerson's offer of direct contactswith North Korea was "a very good signal," whilewarning that a U.S. strike on the North would have "catastrophic"consequences.

British Foreign Secretary Boris Johnson said Thursday that the best way forward on resolvingthe North Korean crisis is to intensify economic pressure on thesecretive state.

Johnson, speaking alongside Japanese Foreign Minister TaroKono in London, said military options in North Korea did not lookattractive.

Kono said North Korea was the most urgent and importantthreat faced by international community.

UN resolutions 'must be implemented'

North Korea tested its most advanced intercontinentalballistic missile on Nov. 29, which it said could put all of the U.S. withinrange, in defiance of internationalpressure and United Nationssanctions.

"Security Council resolutions must be fully implemented,first of all by North Korea, but by all other countries whose
role is crucial," UN SecretaryGeneral AntonioGuterres, speaking to reporters in Tokyo after meetingJapanese Prime MinisterShinzoAbe.

He said he expected a meeting of the UNSecurity Councilon Friday would deliver a strong expression of unity and the need for diplomacy to resolve the issue.

"The worst possible thing that could happen is for us all tosleepwalk into a war."

North Korea justifies its weapons programs as necessarydefence against U.S. plans to invade. The United States, which has 28,500 troops in South Korea, a legacy of the 1950-53 Korean War, denies any such intention.