(Reuters) - U.S. Attorney General Jeff Sessions said on Tuesday the Justice Department would oppose a proposed consent decree to reform the Chicago police department in response to misconduct allegations after the slaying of a black teenager by a white officer.

U.S. Attorney General Jeff Sessions arrives for a meeting with Interior Ministers of the six largest EU countries to discuss security and anti-terror issues at the Groupama Stadium in Decines near Lyon, France, October 9, 2018. REUTERS/Emmanuel Foudrot

Sessions said in a statement the Trump administration was concerned the agreement could lead to a spike in crime in the third-largest U.S. city.

His statement came a day after President Donald Trump pledged to end a “crime spree” in Chicago and urged the city to loosen restrictions on stop-and-frisk tactics by police.

The police reforms are a response to misconduct allegations that emerged after black teenager Laquan McDonald, who was armed with a knife, was shot 16 times by white police officer Jason Van Dyke in 2014. Van Dyke, 40, was convicted of second-degree murder last week.

A video of the incident released in 2015 led to a Justice Department investigation that found Chicago police routinely violated people’s civil rights, used excessive force and racially discriminated against people.

Illinois Attorney General Lisa Madigan sued the city last year, saying its reforms had not gone far enough. She and Mayor Rahm Emanuel’s office agreed on more comprehensive reforms in a proposed consent decree filed in federal court last month.

The reforms include requiring use of de-escalation tactics, ensuring accountability when officers use force irresponsibly and requiring police to track incidents in which officers point their guns.

The Trump administration is concerned that the reforms will undercut policing and that an earlier agreement limiting stop-and-frisk tactics had led to a jump in the number of murders.

In opposing the police reform plan, Sessions cited a 2015 agreement between Chicago and the American Civil Liberties Union (ACLU) that resulted from an ACLU report that cited concerns about police investigatory stops, commonly known as “stop-and-frisk.”

“Chicago’s agreement with the ACLU in late 2015 dramatically undercut proactive policing in the city and kicked off perhaps the greatest surge in murder ever suffered by a major American city, with homicides increasing more than 57 percent the very next year,” Sessions said in his statement.

“Now the city’s leaders are seeking to enter into another agreement. It is imperative that the city not repeat the mistakes of the past - the safety of Chicago depends on it,” Sessions added. He said the Justice Department would file a statement of interest this week opposing the proposed agreement.

Emanuel, in a statement, accused the administration of being “out of touch with reality.”

“If anyone in the Trump administration was paying attention, they would know that as we have made major reforms over the past two years, we have also driven a 30 percent reduction in gun violence,” Emanuel said.