Nancy Pelosi, the speaker in the Democrat-controlled lower house of congress, made the comment on Thursday, as the administration of President Barack Obama considers whether to send more soldiers to fight the Taliban.
"I don't think there's a great deal of support for sending more troops to Afghanistan in the country or in the congress," Pelosi said.
Pelosi is the most senior Democrat to suggest that any move by the White House or Pentagon to send more troops to Afghanistan may face stern opposition in the legislature.
General Stanley McChrystal, the commander of US and Nato forces in Afghanistan, last week sent an assessment of the military situation in the country to the White House.
The classified report does not ask for extra troops to be deployed to Afghanistan but analysts predict that a subsequent report could formally call for more soldiers to be sent to the battlefield.
A briefing on McChrystal's report has take place this week, administration officials have said, but Pelosi said she does not expects to be briefed until next week.
At least 68,000 US troops will be stationed in Afghanistan by the end of the year, following an order by Obama to send 21,000 more soldiers to the country.
Politicians in the House and senate have said that they require compelling evidence that an influx of more troops to Afghanistan will help overcome fighters linked to the Taliban and al-Qaeda.
Source: Al Jazeera (English)