US president Donald Trump will send federal help in an effort to reduce crime in Chicago, he announced in a tweet on Friday.

“Crime and killings in Chicago have reached such epidemic proportions that I am sending in Federal help. 1714 shootings in Chicago this year!” Trump wrote on Twitter.

Attorney general Jeff Sessions told Fox News that under the Trump administration’s plans,  a “Chicago Crime Gun Strike Force” will prosecute firearms cases “aggressively.”

He added that existing anti-crime legislation in Chicago has been inefficient and that the police “have been demoralised in many ways.”

“We’re sending in additional gun investigators. We’ve directed our US attorneys to prosecute these gun cases aggressively,” he said.

“It is critical, critical for the people of Chicago … that we begin to … deport violent criminals who’ve been convicted,” Sessions insisted.

Last year, more than 760 people were shot and killed in Chicago, the third most populous city in the US.

Twenty additional agents from the US Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) will help existing law enforcement officers in the city to combat gun violence.

“This new strike force will significantly help our police officers stem the flow of illegal guns and create a culture of accountability for the small subset of individuals and gangs who disproportionately drive violence in our city,” said Chicago police superintendent Eddie Johnson in a statement.

However, Chicago mayor Rahm Emanuel was critical of the president’s plans, attacking the Trump administration for not acting sooner.

“Apparently this morning the president saw fit to take a brief break from attacking journalists on Twitter to attack one particular major U.S. city instead,” said Adam Collins, a spokesman for Emanuel. “If the president was as interested in taking action on public safety as he is in tweeting about it, we would have seen these resources months ago.”