Capitol Police Chief Kim Dine intends to stay on the job despite submitting a letter of resignation several weeks ago, sources familiar with the situation told Fox News.

Dine sent a message to all rank-and-file officers Friday afternoon committing himself to the department.

"As your Chief, I am immensely appreciative of the work that you do on a daily basis," Dine said in the message. "I have the highest level of confidence in all of our sworn and civilian personnel, and as your Chief, personally reaffirm my continued commitment to this Department.”

Fox News is told that a high-profile incident where protesters were able to get near former Secretary of State Henry Kissinger during a Senate committee hearing -- in turn leading to complaints from lawmakers about security -- helped prompt the resignation offer.

In that late January hearing, Kissinger was testifying before the Senate Armed Services Committee. Protesters disrupted the hearing for about two minutes, standing very close to the witnesses, before they were led away.

The wife of former Secretary of State George Schultz also was slightly injured in the exchange.

During the hearing, Sen. John McCain, R-Ariz., called the demonstration "disgraceful" and the protesters "low-life scum." Afterward, he raised questions about the slowness of the response by the USCP.

U.S. Capitol Police spokeswoman Kim Schneider, at the time, acknowledged the force did not "meet the standards expected of the USCP" during the disruption.

The letter of resignation, though, must be accepted by the three-member Capitol Police Board, which includes Senate Sergeant at Arms Frank Larkin; House Sergeant at Arms Paul Irving; and Architect of the Capitol Stephen Ayers.

They have not and asked for a "plan" from Dine to reform the system.

The Senate hearing scuffle was just the latest in a series of incidents that have made Dine a target of criticism during his relatively short tenure as chief.

In particular, there were concerns over why the Capitol Police let a suspect go after being caught in a high-speed chase at the foot of Capitol Hill -- while President Obama was inside delivering the State of the Union address.

In a separate 2013 incident, federal law enforcement fatally shot Miriam Carey, who was unarmed, after she led U.S. Capitol Police and Secret Service on a high-speed chase which ended by the Hart Senate Office Building.