President Obama, shown speaking to reporters on March 1, 2013, is conducting a round of TV interviews as lawmakers supporting a strike against Syria visit the White House. (Photo by Mark Wilson/Getty Images) (Mark Wilson/Getty Images)

Lawmakers are heading to the White House on Monday to discuss how to rally support for launching a military strike against Syria.

Republican Reps. Tom Cotton (Ark.) and Peter King (N.Y.), both outspoken proponents of a strike, were spotted walking into the White House in the early afternoon.

Rep. Eliot Engel (D-N.Y.), another supporter, is headed there later in the day.

The sessions come as the White House issued a revised list of countries that back using military force against Syria in the wake of last month's chemical weapons attack against civilians. The expanded list includes Albania, Croatia, Denmark, Estonia, Germany, Honduras, Hungary, Kosovo, Latvia, Lithuania, Qatar, Romania and the United Arab Emirates.

Philip Rucker contributed to this report.