US calls for tighter enforcement of UN sanctions against North Korea.

The United States on Monday called for tighter enforcement of UN sanctions against North Korea over its nuclear activities and its artillery attack last week on the rival South.
  
The United States expects UN Security Council sanctions committee experts "to intensify their important ongoing efforts to tighten sanctions enforcement," US ambassador to the United Nations Susan Rice said.
  
She called last week\'s deadly attack on Yeongpyeon island "outrageous" and said the United States would "work with the international community to maintain peace and security in this region as we simultaneously confront the threat posed by North Korea\'s ongoing nuclear activities."