WASHINGTON - Americans are more accepting of immigration than in years past, with 40 percent saying current levels should be maintained, increasing the possibility that Congress will pass immigration reform, Gallup found in a poll released Thursday.

Thirty-five percent say immigration should be decreased, and 23 percent - the highest rate Gallup has on record - said immigration should increase.

The figures stand in sharp contrast to a decade before, especially after the September 11, 2001 terror attacks, when nearly half of Americans favored a decrease in immigration and a mere 12 percent to 18 percent wanted an increase.

The findings come as Congress meets this week to hammer out how they should handle immigration reform and just weeks after the Senate passed a bill to overhaul the nation's broken immigration system. House Republicans met Wednesday to discuss the issue for the first time in seven years, U.S. media reported.

Non-whites have consistently been more likely than whites to favor increased immigration. After the September 11 attacks, support for increasing immigration declined sharply among non-whites but recovered in 2006. At that time, support among whites increased slightly. Support among both groups retreated in 2009, possibly in response to the worsening economy, Gallup found.

But since then, Gallup's annual trends document a clear, steady increase in support for immigration, with support among whites rising enough in the past two years to nearly match that of non- whites, Gallup found.

Among nonwhites in this poll, blacks and Hispanics have similar preferences on immigration levels, with 67 percent of blacks and 68 percent of Hispanics in favor of maintaining or increasing immigration. Historically, though, Hispanics have been more likely to hold these views.

"The current public opinion environment relative to immigration, broadly, may be more conducive to passing comprehensive legislation to address illegal immigration than it was the last time Congress made a serious effort to pass it in 2007," Gallup said.