US is to tighten sanctions on North Korea and step up diplomatic moves aimed at pressuring the country to end its nuclear and missile programmes. President Donald Trump's strategy was announced after a special briefing for all 100 US Senators. <br/><br/>Earlier, the top US Commander in the Pacific defended the deployment of an advanced missile defence system in South Korea. Tensions have risen amid fears the North is planning new weapons tests.<br/><br/>The US already has extensive sanctions in place on North Korea, including a blanket ban on trade and a blacklist of anyone dealing with North Korea. It is not clear what further sanctions Washington could impose.

United States is going to tighten sanctions on North Korea and step up diplomatic moves aimed at pressuring the country to end its nuclear and missile programmes. <br/><br/>President Donald Trump's strategy was announced after a special briefing for all 100 Senators. <br/><br/>Earlier, the top US commander in the Pacific defended the deployment of an advanced missile defence system in South Korea. <br/><br/>Tensions have risen amid fears the North is planning new weapons tests. <br/><br/>A joint statement issued by Secretary of State Rex Tillerson, Defense Secretary Jim Mattis and Director of National Intelligence Dan Coats said the United States seeks stability and the peaceful denuclearisation of the Korean peninsula.