Lyndon Johnson actually said...

I want to thank you again for your welcome.

May we prove worthy of the honor that you and your comrades in arms are bringing to this great land of ours.

Hundreds of thousands of their fellow Americans have died to bring us to the point where nations will look for other ways than war to settle...

Their sons have joined a conflict as difficult and demanding, against an enemy as tough and resilient, as any American arms have ever faced ...