The assault on Paris is over for now, US President Barack Obama said from Tennessee on Friday, but the greater threat from Islamic extremism remains.This was the president's first reaction to a pair of violent showdowns that gripped the people of France on Friday. One shootout at a kosher market in Paris, and another in a warehouse just outside the city, took the lives of four hostages and three hostage-takers, including the two suspected murderers of Charlie Hebdo journalists earlier this week."We're hopeful that the immediate threat is now resolved," Obama told an audience, gathered to hear a speech on the president's efforts at education reform. "But the French government continues to face the threat of terrorism."Counter-terrorism officials briefed Obama right before his remarks, and the White House says US officials are in "minute by minute" contact with their French counterparts, offering whatever assistance France may request."The situation is fluid," he continued. Addressing the people of France, he said, "The United States stands with you today, stands with you tomorrow."