<span style="color: #222222;">US military said Washington is keeping a close watch on North Korea following reported activity at a rocket launch site there. <br />''<br />''The head of the US Indo-Pacific Command, Admiral Phil Davidson, said in Singapore today that the US is working with countries including South Korea, Japan, Australia, New Zealand, Canada and France to enforce sanctions against North Korea at sea. <br />''<br />''He said maritime patrol aircraft and ships are watching for any sanction breaches via methods like ship-to-ship transfers.</span><br />