US President Donald Trump has said there is a good chance that he will declare a national emergency to build his proposed wall along the US Mexico border to prevent flow of illegal immigrants into the country.<br />''<br />''Talking to the reporters at White House Mr Trump said, he would use his State of the Union address next week to once again make a case for the barrier. He also asserted that he has a very strong legal standing on the issue of declaring emergency.<br />