Just hours after an Amtrak derailment that killed seven people and injured dozens of others, the White House assailed Republicans for supporting legislation that would cut funding for Amtrak by $250 million.

White House press secretary Josh Earnest cautioned that the cause of the Amtrak derailment is still under investigation, but said President Obama has supported a nearly $1 billion increase for Amtrak in this year's budget blueprint.

"Republicans unfortunately are considering legislation that would cut funding by a quarter of a billion dollars a year," he said. "That's not consistent with the kind of priorities that the president is trying to advance."

Earnest's remarks came just minutes before a House panel approved a measure on straight party lines that reduced funding for Amtrak and voted down a Democratic amendment that would have boosted funds for the passenger railroad by $1 billion to $2.4 billion.

Republicans pushed back against criticism from Democrats about the timing of the vote to cut Amtrak funding and said any funding increase would have to be offset elsewhere in the budget.

"Don't use this tragedy in that way. It was beneath you," Rep. Mike Simpson, R-Idaho, reportedly told Democrats Wednesday.

CNN, citing "a source," reported that the derailed Amtrak train is believed to have been traveling at 100 miles per hour as it approached a turn rated at 50 mph.

Earnest said the president's support for increased Amtrak funding is part of his push for greater infrastructure spending across the board.

"The president does believe that we need upgrades in our infrastructure system, including our rail systems," Earnest said, noting that the added construction would create jobs.