The time has come for the United Nations to place sanctions against South Sudanese leaders, said Donald Booth, the U.S. envoy to South Sudan and Sudan, at a gathering of press and policymakers in Washington on Thursday.

Such sanctions by the greater international community will send a "clear message," Booth said. "A unified signal that this senseless war is unacceptable and that those responsible will pay a price." Booth did not rule out the potential for an arms embargo, something the U.S. has supported.

"The patience with the process is wearing thin," he said at the Atlantic Council think tank gathering, according to the Associated Press.

Because the 45-day deadline set for peace talks to yield a solution has expired, Booth said the U.S. should now consider "acting decisively."

Several military commanders have already been sanctioned by the U.S., according to Booth, and considering the lack of progress with peace talks, Booth said that neighboring African countries are now more supportive of sanctions than they have been in the past.

While specific individuals to be targeted by penalties were not named, Booth blamed South Sudan's leaders for ruining an opportunity for peace and prosperity when the countries broke away in 2011, reported the Associated Press.

Booth almost mentioned the "dire" economic and political problems faced by Sudan. The government made promises for a national dialogue aimed at easing tensions, but Booth said the status of the dialogue is not certain.

The U.S. has been attempting to establish a cease fire in South Sudan, said AP, where government loyalists have been fighting for power for almost a year.

South Sudanese government spokesperson Michael Makuei argued earlier this week that the 45-day deadline should not be considered to have passed until negotiators have one more opportunity to conduct talks, according to Radio Tamazuj.

"We did not demand the recess - it is the mediators who decided, and we went on recess from the 4th. And from the 4th up to our going back, these days will not be counted within the 45 days."