WASHINGTON - A senior official in the Obama administration doused hopes on Wednesday that the Canadian border will be treated differently than the beefed-up Mexican boundary where drug violence is escalating and countless illegal immigrants flood into the United States every day.

"One of the things that we need to be sensitive to is the very real feelings among southern border states and in Mexico that if things are being done on the Mexican border, they should also be done on the Canadian border," Janet Napolitano, the secretary of homeland security, told a Canada-U.S. border conference.

The daylong Brookings Institution event featured dozens of participants from both countries discussing ways in which the movement of goods and people across the Canada-U.S. border could be facilitated. Napolitano's remarks closed the event on an almost depressing note.

"We shouldn't go light on one and heavy on the other," she said of the Canadian and Mexican borders.

"This is one NAFTA, one area, one continent, and there should be parity there. I don't mention this to suggest that everyone in this room will agree with that, I mention it to suggest it's something I have to deal with, and so I ask for your sympathy."

Her comments came after she testified at U.S. Senate hearings into growing drug violence at the U.S.-Mexican border that's prompted President Barack Obama to redeploy more than 500 federal agents to border posts and the Mexican interior.

He's also redirected US$200 million to combat smuggling of illegal drugs, money and weapons.

The United States is concerned that drug wars that killed 6,000 people in Mexico last year will spill across the border. Mexico says that American guns are fuelling the violence.

Napolitano told the hearing it would probably take weeks to complete a contingency plan for sending U.S. National Guard troops to border areas.

She later had a sobering message for Canadians hopeful that, under Obama, there would be freer movement of goods and people across a Canada-U.S. border that looks almost Utopian compared to the chaos at the American-Mexican boundary: it's a real border and things aren't easing up anytime soon.

"It's as though there's not a border at all," Napolitano said of the close relationship between the two countries, particularly among those living in border communities.

"People are used to going back and forth, and the hockey teams go back and forth ... people just don't think of it as two different countries. But the reality exists that there's a border there too."

She also said there would be no further delay of the Western Hemisphere Travel Initiative despite a Democratic congresswoman's remarks to the conference earlier in the day that neither the United States nor Canada was prepared to make the June deadline.

Louise Slaughter, a powerful House Democrat, said she plans to introduce a bill delaying implementation until June 1, 2010. But Napolitano said the Obama administration is determined not to postpone it any further.

"We are prepared to go forward in June," she said, while acknowledging "there is a lot of concern on both sides of the border...are we really ready?"

The last phase of WHTI has been delayed several times. As of June 1, adults entering the United States from Canada, the Caribbean, Bermuda or Mexico will be required to present a passport.

Napolitano said to delay the initiation date again would send the wrong message to both Canadians and Americans that neither country is serious about getting the program up and running.

"We're exploring what we can do with Canada to publicize that this deadline is coming; it is real. And it really goes to that change of culture -- there is a sense in some places that we've always gone back and forth, why do I need to get a passport, and we're going to get some of that," she said.

"But it is a real border and we need to address it as a real border."