Johnson & Johnson said on Tuesday it will contribute up to $1 billion more to a potential settlement of lawsuits alleging it and other companies fueled the U.S. opioid epidemic, bringing its total payment to $5 billion.

The New Brunswick, New Jersey-based drugmaker had agreed last October to a $4 billion settlement framework negotiated with a group of state attorneys general.

That proposal also called for the drug distributors McKesson Corp, Cardinal Health and AmerisourceBergen to pay a combined $18 billion, but the framework met resistance from some states and local governments.

Negotiations have been ongoing since then, and the dollar amounts have been shifting. J&J in a statement said the additional $1 billion reflected continued negotiations and said additional terms are being finalized.

Paul Hanly, a lead attorney for local governments pursuing federal lawsuits against opioid manufacturers and distributors, said in a statement the plaintiffs' lawyers were "very pleased" with J&J's agreement to resolve the cases.

"We are hopeful other companies defending the numerous litigations will see the wisdom of this step forward," he said.

Representatives for the distributors and several state attorneys general did not respond to requests for comment.

More than 3,000 lawsuits have been filed nationally largely by states, counties and municipalities seeking to hold drug companies responsible for the U.S. opioid addiction epidemic.

The lawsuits generally accuse drugmakers including J&J of deceptively marketing opioids and distributors of ignoring red flags indicating the painkillers were being diverted for improper uses.

The companies including J&J (JNJ) deny wrongdoing. J&J is separately appealing a $465 million judgment the state of Oklahoma won against it in the first case to go to trial in the litigation.