``We believe we need to engage with China and talk to China precisely to advance our national security, in cases such as India and Pakistan, and North Korea going nuclear,'' State Department spokesman James Rubin said yesterday.

He said like other countries, China desires to obtain sensitive information and Washington has not downplayed any evidence on the Chinese espionage.

``We have been operating, as every administration has been operating, under no illusions as to China,'' he said adding, ``It is inconceivable that we would downplay concerns about espionage in a case that took place in the 1980s.''

Rubin said Secretary of State Madeleine Albright during her visit to China emphasised Washington's concern on violation of human rights.

He said the fact thatWashington is worried about proliferation problems is not because of some hidden agenda. It is the result of a bipartisan concern about Chinese policies in cracking down on human rights and in the area of proliferation.

Further defence of the Clinton administration's China policy came from Vice-President Al Gore who pointed out that Beijing's economy and its role in the world was growing.

``China is the most populous country in the world. Its economy is growing, and its role in the world is going to grow whether we want that or not,'' Gore said while appearing in a programme on CNN.

He linked the US relationship with China to Beijing's human rights record and unfair trade practices. ``Having a relationship with them within which we can try to affect their behaviour and improve human rights, eliminate unfair trade practices and bring about the kinds of changes that will lead to further democratisation in China, these things are in our interest,'' he said.

Gore said the Clinton administration hadpursued such a policy ``without compromising our principles in any way." Senior US officials, for their part, rejected allegations that the administration had moved too slowly to counter China's efforts to steal sensitive American military technology.

Scrambling to halt congressional criticism, the White House said it had moved rapidly and effectively to tighten security. White House spokesman Joe Lockhart, speaking in Honduras during Clinton's tour of Central America, said: ``The administration moved rapidly in 1997 when this came to our attention, took the steps we needed to develop safeguards against any illegal transfer.''

But legislators are angry for what they regard as foot-dragging in investigating suspected breaches, followed by the firing on Monday of a Taiwan-born scientist at the Los Alamos National Laboratory in New Mexico.