The powerful US business lobby warned Tuesday it would not walk in "lock-step" with President Barack Obama despite recent improved ties, but offered qualified backing for key legislative fights ahead.

After two years of spats with the White House, the US Chamber of Commerce said it would support Obama-backed moves to secure trade deals, tax reform, more infrastructure spending and debt reduction.

Just weeks before Obama makes a high profile address to the chamber -- which claims to represent three million businesses -- chief executive Thomas Donohue struck a conciliatory tone, and offered the prospect of help on battles set to mark the second half Obama's term.

"We'll continue to have our differences from time to time with the White House on some issues, but on many of them we will work together," he told members.

But, he added, "no one should expect the chamber to march in lock step with anyone" -- a simultaneous warning to the White House and Republicans who control one half of Congress.

Since Obama took power, the chamber -- angered by Wall Street and healthcare reforms -- has spent tens of millions of dollars supporting Republicans, much to Democrats' chagrin.

But since legislative elections in November the shrill tone of arguments between the Chamber and the administration has been toned down.

"It has has never been personal with us," said Donohue, citing support for some of the administration's policies, including unpopular spending to stimulate the economy.

"It is interesting to look at the two year relationship with the White House," he said, "we have supported them on an extraordinary number of issues, including the stimulus."

Obama, faced with unemployment levels stuck close to 10 percent, has placed business-savvy staff in key positions and moved to improve relations with big business.

The recent appointment of William Daley as White House Chief of Staff and Gene Sperling as head of the National Economic Council were both welcomed by the chamber.

"The new people will be helpful," said Donohue, "Bill Daley is a real pro and we have worked with him for many years, and Sperling has done this before."

Despite record profits, large firms have been slow to rehire workers. Changing that trend is seen by many as the key to reducing unemployment.

Avoiding the appearance of open warfare with the business community would also be a major political boon for Obama heading into the 2012 presidential elections.

It remains to be seen if the new-found amity will stand up to the nitty-gritty of US law making. But, for now, the chamber is sounding a conciliatory tone.

Donohue cited the chamber's support for trade deals with South Korea, Panama and Colombia; moves to improve the US's creaking infrastructure and reduce its crippling debt, all issues Obama has vowed to tackle.

The chamber, while arguing for lower corporate tax rates, also hinted at a more cooperative approach when it comes to highly politically fraught efforts to reform America's fiendishly complex tax code.

"We are not going to win it all and we have to be part of the solution, not part of the problem," Donohue said.

Obama is scheduled to address the US Chamber of Commerce on February 7.