Liberal leader Michael Ignatieff says that Prime Minister Stephen Harper is sending a "troubling" message to the United States on Canada's role in Afghanistan.

Ignatieff made the comments in Washington, where he attended a conference on the Afghanistan mission Thursday morning and spoke privately with a number of top Obama administration officials.

"I came to the conference to say that I believe very passionately in what we are trying to do in Afghanistan, which is to stabilize the country . . . so that Afghans can live the semblance of a normal life," he told reporters Thursday evening in Washington.

"I get a sense in the prime minister's approach to this, in that he's disinvesting," Ignatieff said.

Ignatieff said Harper is conveying a sense of "futility" about the Afghan mission in interviews with U.S. media.

Richard Holbrooke, U.S. President Barack Obama's special ambassador for Afghanistan and Pakistan, also spoke at the conference.

Ignatieff had dinner with Holbrooke and U.S Central Command leader, Gen. David Petraeus, on Wednesday.

"I said to Mr. Petraeus, 'Were we in government you could count on us as strong partners', but I made it very clear, that we will not continue the combat mission in Kandahar after 2011," Ignatieff said.

However, Ignatieff said Canada should continue to help Afghanistan after 2011, but in humanitarian or political terms.

Ignatieff spoke behind closed doors Thursday morning at a conference organized by the Carr Center for Human Rights Policy at Harvard University, where he was once a professor.

Ignatieff also spoke about the economy and other issues with officials on the trip to Washington meant to highlight the close relationship between the Liberal leader and the Obama administration.

Ignatieff talks Napolitano

Ignatieff also spoke to a top Obama official about U.S. Homeland Security Secretary Janet Napolitano after she made two controversial comments recently about Canada.

Ignatieff says he told Larry Summers, Obama's top economic advisor, that Napolitano is mistaken if she believes that Canada's border poses a security risk to the United States.

Napolitiano suggested in a Tuesday speech that Canada is much more lax than the U.S. about immigration, only days after wrongly saying the 9-11 terrorists entered the U.S. through Canada.

She was slammed for the comments, both at home and in Canada. Immigration Minister Jason Kenney told CTV's Power Play that she was just "wrong." Several Republicans have called for her to resign or to be fired.

Ignatieff says the remarks raise "strong concerns" for Canadians and told Summers that the former Arizona governor has "ill-founded" suspicions about Canada.

Ignatieff is expected to attend a dinner hosted by Obama's White House foreign policy adviser Samantha Power and her husband Cass Sunstein.

Sunstein works for Obama and is rumoured to be in line for the president's first Supreme Court appointment.

Summer, a close friend of Ignatieff's, is also expected to attend the dinner.

Meanwhile, Ignatieff also meet with Barney Frank, the head of the House financial services committee, and discussed the global economic crisis.

Liberals insiders say they're hopeful that Ignatieff and Obama can meet later this year in Washington.

Ignatieff met with Obama for about 35 minutes during his recent visit to Ottawa.