By Justin Webb BBC correspondent in Texas

The president has been telling audiences in the last few days that he is sorry his wife can't be with him.

"You see we've had rain at the Texas ranch," he tells them, "so Laura's had to stay behind to sweep the porch - we've got the president of China coming to visit."

The White House will hope that... President Jiang will turn the screws on the its erratic regional ally (North Korea)

A visit to the Bush ranch in Texas - his beloved Crawford wilderness - is not quite as homespun as the president likes to make it sound.

There is more there than just a porch and a simple home.

But he is quite within his rights to suggest that the arrival of a foreign leader in Crawford is not an everyday occurrence.

A get-together on the president's Crawford ranch is in fact a prize awarded to few world leaders.

So the very fact that President Jiang is in Texas could be taken as a compliment to him and a sign that the White House is reaching out to China.

US hopes

The Chinese leader has returned the favour before even setting foot in the ranch by making a speech in which he promised that China and America could act together to combat what he called the scourge of terrorism.

A visit to Bush's ranch is a prize awarded to few world leaders

"We stand ready to keep in touch with the US and co-operate more closely to promote peace and stability," he said.

President Bush would like to hear two things from the Chinese leader when they hold their short formal session of talks.

First he wants an assurance that China will not veto America's proposed UN security council resolution on Iraq. He may well get it, or at least a nod in that direction.

China certainly sees itself as guarding against what some Chinese leaders have seen as American expansionism. But China has also been much more willing recently to work to halt the proliferation of weapons of mass destruction.

And that also leads to hope in the White House that the second big subject for the summit might also be a positive one.

Recent changes

In the past the Americans have accused the Chinese of assisting North Korea in its nuclear weapons programme.

This summit is evidence of a desire on both sides to make progress - cautious progress - towards a closer relationship in the future

But experts say there has been a change in recent times.

President Bush's spokesman has said he does not believe that the Chinese want to see a Korean peninsula that is home to nuclear weapons.

The White House will hope that optimism is justified and that President Jiang will turn the screws on the its erratic regional ally.

Finally there is the issue of US-Chinese military co-operation.

That was frozen more than a year and half ago after the crash landing of an American spy plane in China.

New priorities

Perhaps the moment has arrived when both sides feel the world has moved on to a sufficient extent to re-open high level talks - senior officials in the US Defence Department say the subject is on the agenda.

Some hawks in the US administration would probably not regard the re-opening of talks as a wholly good thing.

They complained in the past that the Chinese usually gained more knowledge about American military plans than they revealed about Chinese operations.

But these are changed times.

New priorities are in place both in Washington and in Beijing.

This summit is evidence of a desire on both sides to make progress - cautious progress - towards a closer relationship in the future.