New York ? As the protest on Wall Street enters its fourth week, police officers are keeping their posts around the perimeter of the park at the center of it all. And with no end in sight, the cost of constant police surveillance will continue to rise at a time when Mayor Michael Bloomberg has ordered citywide budget cuts.

The New York Police Department already has spent $1.9 million, mostly in overtime pay, to patrol the area near Zuccotti Park, where hundreds of protesters have camped out for several weeks. Though cold weather is on the way in, protesters don’t plan on leaving anytime soon. They’re prepared to stay put for the long haul.

“The bottom line is that people want to express themselves, and as long as they obey the laws, we allow them to,” Bloomberg told reporters Monday when asked about the protesters’ staying power. “If they break the laws, then we’re going to do what we’re supposed to do — enforce the laws.”

Last week, Bloomberg ordered all agencies to prepare to cut expenses by a total of $2 billion during the next 18 months. Police Commissioner Raymond Kelly said the budget cuts may cause the cancellation of a new class of police officers entering the academy in January.

Police officials would not comment Monday on whether the Occupy Wall Street protest would have any bearing on how the budget cuts would play out. A spokesman for Bloomberg declined to comment on any financial issues.

“We always prefer to not spend overtime, but again, this is a big complex city, lots of things going on,” Kelly said last week, describing the protesters’ effect on the NYPD. “And we have to spend overtime for unplanned operations.”

The protesters say they’re fighting for the “99 percent,” or the vast majority of Americans who do not fall into the wealthiest 1 percent of the population; their causes range from bringing down Wall Street to fighting global warming. The movement gained traction through social media, and protests have taken place in several other cities nationwide.

On Monday, the Rev. Al Sharpton and rapper Kanye West made impromptu appearances at the park. A group of mothers also took small children downtown to teach them about the movement, calling themselves the “99 Percent School.”