Updated

House Speaker Nancy Pelosi and Defense Secretary Robert Gates on Sunday expressed divergent views on the July 2011 withdrawal date for troops in Afghanistan, while Pelosi had sharp words for White House Press Secretary Robert Gibbs.

Speaking on ABC's "This Week," with new anchor Christiane Amanpour making her debut, Gates said he believed July 2011 would initially bring limited drawdowns of troops.

"As we are successful, we'll probably accelerate. But, again, it's -- it will depend on the conditions on the ground," Gates said.

Gates said enough U.S. forces would still be in the ground in Afghanistan to deter the Taliban from mounting a new offensive even after drawdowns begin.

"We need to re-emphasize the message that we are not leaving Afghanistan in July of 2011," Gates said. "The president has been very clear about that. And if the Taliban are waiting for the nineteenth month, I welcome that, because we will be there in the nineteenth month and we will be there with a lot of troops."

Pelosi, responding to comments made by Vice President Joe Biden on "This Week" last Sunday, in which he said the initial drawdown might be just "a couple thousand troops," said "Well, I hope it is more than that."

She said that while she does not think Americans believe the drawdowns will mean "'Turn out the lights and let's all go home on one day,'" she thinks they expect it to mean more than a few thousand troops.

President Barack Obama, speaking on CBS's "Sunday Morning," said the U.S.'s goals in Afghanistan are modest.

"Nobody thinks Afghanistan is going to be model Jeffersonian democracy," Obama said. "What we're trying to do is a difficult but modest goal: Don't allow terrorists to operate from this region, to plan attacks against the U.S. with impunity. That can be accomplished."

Pelosi also claimed not to put much stock in comments made on July 11 by White House Press Secretary Robert Gibbs regarding the possibility that Republicans could retake the House in the November elections.

"There's no doubt there are enough seats in play that could cause Republicans to gain control," Gibbs said on NBC's "Meet the Press."

"With all due respect, I don't spend a whole lot of time thinking about what the president's employees say about one thing or another," Pelosi said.

Pelosi expressed confidence in Democrats' chances in November.

"We have a solid plan of messaging and mobilizing at the grassroots level and management of our campaigns," she said. "And we have a two-to-one advantage money-wise. So we feel very confident about where we are, whether that's well known to that gentleman or not."