Obama rebukes Trump, says tired of trash-talking of troops

In a veiled attack on Donald Trump for his remarks against the parents of a Muslim-American soldier, President Barack Obama said he is tired of some people "trash talking" US military and troops.

As the Republican presidential candidate continued to hurl attacks on the family of US Army Captain Humayun Khan, Obama praised the sacrifice of American armed services members and their families at the Disabled American Veterans convention.

"As commander in chief, I'm pretty tired of some folk's trash talking America's military and troops," Obama said, without naming anyone.

"Our military is somewhat smaller after two major ground wars come to a close, that's natural. We are going to keep them doing everything we need to do to improve readiness and modernise our forces," he said.

Setting some facts straight, Obama said America's army is the best trained, best equipped land force on the planet, its Navy is the largest and most lethal in the world and the precision of and reach of its Air Force is unmatched.

"Our Marines are the world's only truly expeditionary force. We have the world's finest Coast Guard. We have the most capable fighting force in history and we're going to keep it that way," he said.

"No ally or adversary should ever doubt our strength and our resolve and we will keep pounding ISIL and taking out their leaders and pushing them back on the ground. And united with a global coalition, we will destroy this barbaric terrorist group. They will be destroyed," he said.

"In the face of Russian aggression, we're not gonna turn our back to our allies in Europe. We're going to stay united in NATO which is the world's strongest alliance. From the Asia-Pacific, to Africa, to the Americas, the United States and our armed forced will remain the greatest force for freedom and security and peace that the world has ever known," Obama said.

Obama said no one has given more for the freedom and security than the Gold Star families, to which belong the parents of Humayun Khan.