Washington - Toughening gun laws will do nothing to deter future terror attacks, the main US gun lobby said on Tuesday, urging leaders to focus their fight on Islamic extremism, not Americans' right to bear arms."Radical Islamic terrorists are not deterred by gun control laws," wrote Chris Cox, executive director of the National Rifle Association Institute for Legislative Action, the NRA's lobbying arm, in an article responding to Sunday's deadly attack on a gay bar in Orlando.Strict gun control"It's time for us to admit that radical Islam is a hate crime waiting to happen," wrote Cox, whose organisation has endorsed the Republican Donald Trump in the White House race, in USA Today."The only way to defeat them is to destroy them - not destroy the right of law-abiding Americans to defend ourselves. "The San Bernardino terrorist attack wasn't stopped by California's so-called 'assault weapons' ban. The gun ban in Brussels didn't prevent the terrorist attack there. And France's strict gun control didn't stop the two attacks in Paris, committed with fully-automatic rifles and grenades."Cox charged that "political correctness" on the part of President Barack Obama's administration had prevented the FBI from stopping shooter Omar Mateen - who had been investigated for suspected radicalism but against whom they were unable to build a case.The NRA lobbyist hit back at both Obama and Democratic White House hopeful Hillary Clinton after she renewed her call for tougher gun controls including a ban on assault weapons."They are desperate to create the illusion that they're doing something to protect us because their policies can't and won't keep us safe," Cox said."Law-abiding gun owners are tired of being blamed for the acts of madmen and terrorists."Gun violenceThe Orlando mass shooting, which left 49 dead, has once again unleashed gun control advocates clamouring for curbs on weapons sales. But the carnage also shows the scale of their challenge in a country where Mateen, a 29-year-old once flagged on an FBI watch list, was able to commit mass murder with a legally-bought assault rifle.Since Obama took power in 2008, he had been stymied in his bid to curb gun violence by a Republican-led congress and a powerful gun lobby that reject any moves to rein in gun ownership in the name of the Constitution's Second Amendment.