Christie pushed for the deal, and Barchi was brought on board to make it happen after a law was signed last year to allow the restructuring.
The university president has been sidetracked lately, however, by a campus basketball scandal, which has cost several university officials their jobs.
The scandal erupted when ESPN aired video showing the now-fired basketball coach, Mike Rice, verbally and physically abusing players.
"This is an important thing to me as you all know, so I'm going to make sure everything that needs to get done from the state's perspective is done . . . because I think it will make Rutgers a significantly better institution," Christie said Friday of the merger.
Barchi told an Assembly budget panel last week he sees "a clear line of sight" to the deadline and guaranteed it would be met.
It was evident from his testimony, however, that significant obstacles remain.
For one, he said, more than half of the 4,000-plus issues associated with the merger had been dealt with, which means some number approaching 2,000 remain unresolved.
Because there is no money in Christie's proposed budget specifically for execution of the merger, the $70 million to $75 million in estimated one-time costs will be absorbed by Rutgers.
Barchi said students would not be asked to cover those costs through higher tuition. He said the university would defer projects and maintenance and program expansions.
The latest cost projection is 50 percent higher than the highest estimate given when the overhaul was being considered.
Barchi also told the panel he expects Rutgers' credit rating to drop by up to two notches as the university absorbs debt from the financially riskier UMDNJ. He said he expects the dip to be temporary.
One issue that has elicited recent complaints from faculty and staff at Rutgers-Newark concerns the fiscal autonomy the Newark and Camden campuses were promised in the deal.
The two satellite campuses are to have their own budgets separate from the New Brunswick campus', according to the restructuring law, and more independence in how to spend their allocation. However, Christie's budget shows only one budget line for Rutgers, with $487 million in state aid.
"We had nothing to do with a single line item," Barchi told the Assembly panel. He said the administration asked for the single budget line, and said it would be fixed by July 1.