Alvin Baez ReutersA protester holding Puerto Rico’s flag takes part in a march in San Juan to improve health care benefits

"Friends are there when times are tough, and we have your back", he said when announcing the new office along with the governor of Puerto Rico and City Council Speaker Melissa Mark-Viverito.

The marchers, estimated in the tens of thousands by the governor's office, shut down a major San Juan thoroughfare.

After being followed all the way to Puerto Rico by a television reporter seeking an opportunity to ask him questions he deems "off topic," Mayor Bill de Blasio today defended his media strategy and said there would be "regular opportunities" for journalists to question him. "The truth in that our federal authorities doesn't treat Puerto Rico fairly on Medicaid ..."

"Puerto Rico's problems are New York's problems, and we are going to be there for them 100 percent", Cuomo said.

The demonstrators were protesting Medicaid reimbursements in the USA territory that officials say are 70 percent lower than on the US mainland and Medicare reimbursements that are 40 percent lower.

Padilla noted that the friendship and commitment shown by Cuomo and New York's many federal and state elected officials is particularly gratifying, and it will be critically important to helping Puerto Rico avert a healthcare and economic crisis.

In a report that aired on CBS that evening, Ms. Kramer said she'd wanted to ask Mr.de Blasio about a homeless encampment and other issues-and said other mayors she had covered had been more open to questions.

De Blasio was not at the late morning press conference, which was held hours before he arrived.

Gov. Andrew Cuomo said Thursday that the new office will promote "mutually beneficial" tourism opportunities and economic ties. They are part of New York.

For the past two years, he has made long weekends out of his business trips to Puerto Rico - twice bringing his wife for mini-vacations - but this year he stayed for just one day.