US President Barack Obama has praised France as a model ally in a world that must do more to meet common threats, laying on the full flourish of a state visit for President Francois Hollande.
Obama hailed France an increasingly key partner in the fight against Islamic extremism in Africa, nuclear proliferation and climate change, as he welcomed Hollande on the White House lawn.
The presidents stood side by side framed by the red, white and blue of their nations' flags as a 21-gun salute split the air and ranks of troops in dress uniform stood to attention.
"Like generations before us, we now have the task not simply to preserve our enduring alliance but to make it anew for our time," Obama said.
"No one nation can meet today's challenges alone or seize its opportunities.
"More nations must step up and meet the responsibilities of leadership, and that is what the United States and France are doing together."
While disengaging from wars in Iraq and Afghanistan, Washington has pressed its European allies to do more to protect their own security in operations such as the Libya war - albeit with military and logistical support that only the US superpower can provide.
Hollande paid tribute to the sacrifice of US soldiers in World War II and said the two old allies stood for bedrock principles of universal rights.
"Today France and the United States still stand side by side to make these values prevail," Hollande said.
"We stand together with the United States to address the threats of the proliferation of weapons of mass destruction and chemical weapons, together to solve the crises faced by the Middle East, together to support Africa's development, and together to fight global warming and climate change."
Hollande will be without a date at the state dinner in a huge marquee sumptuously decorated with French touches, after turmoil in his love life made global headlines.
The authenticity of the Franco-US alliance, often tumultuous, lies in its resilience: ties are now tightening a decade after they ruptured over Iraq.
