Updated

Two members of the Senate are pressing for significant changes to how presidents consult with Congress on sending the military into war.

Sens. John McCain, R-Ariz., and Tim Kaine, D-Va., unveiled legislation on Thursday that would repeal the 1973 War Powers Resolution, often ignored by presidents of both parties, and replace it with a new law that requires greater consultation and a congressional vote within 30 days on any significant armed conflict.

"The Constitution gives the power to declare war to the Congress, but Congress has not formally declared war since June 1942, even though our nation has been involved in dozens of military actions of one scale or another since that time," McCain said. "There is reason for this: The nature of war is changing."

Since the Vietnam War-era resolution, the U.S. military has been involved in several conflicts, most recently when President Barack Obama sent American warplanes to protect civilians in Libya in 2011. The operation touched off a fierce debate in Congress over whether the president had exceeded his authority.

Obama's initial call last year for congressional approval for U.S. military action against Syria revived the debate.

"Forty years of a failed war powers resolution in today's dangerous world suggests that it's time now to get back in and to do some careful deliberation, to update and normalize the appropriate level of consultation between a president and the legislature," Kaine said.

The proposal would require the president to consult with Congress "before ordering deployment into a 'significant armed conflict,' or, combat operations lasting, or expected to last, more than seven days." The consultation must occur within three days of deployment.

Humanitarian missions and covert operations would be excluded.

The measure also would require a vote in Congress on the military operation within 30 days.

The proposal is based on the work of bipartisan National War Powers Commission, which was led by former Secretaries of State James Baker and Warren Christopher.