NEW YORK (NYTIMES) - Joe Biden's presidential campaign, which has faced criticism from some Democrats worried about his team's general election readiness, is planning a substantial expansion of its operation and eyeing an ambitious battleground map even as the question of when Biden will resume in-person campaigning remains unclear.

In an hourlong briefing with reporters on Friday (May 15), senior campaign officials pledged to have "over 600 organising staff responsible for battleground states" in place by next month as they pursue an "expanded map" with Arizona at the "top of the list" of new opportunities.

They also said that they had doubled the size of the digital team "and it is growing," and that they planned to implement a new livestreaming platform as they navigate the challenges of campaigning virtually during the coronavirus crisis.

The campaign, which is seeking to cast the election as a referendum on President Donald Trump, expects traditional, on-the-ground organising to take place sometime this year, said Biden's campaign manager, Jennifer O'Malley Dillon.

But when that begins - or when Biden leaves his Wilmington, Delaware, home to campaign - will be determined by public health recommendations, she said.

"The most important thing for us and for the campaign is public safety and the safety of the vice president, the people around him, the staff, the press corps, the Secret Service," O'Malley Dillon said, noting the current stay-at-home order in Delaware. "We will travel physically to places when the time is right, driven by the experts and the guidelines that come and not a day before."

But, she stressed, "I truly believe voters, our volunteers, our activists, our supporters, get as much on hearing from the VP and connecting with him in a virtual setting now as they would if he was out in person. So I really feel like we're doing the business of campaigning in an aggressive way."

O'Malley Dillon also sketched out the Biden campaign's view of the battleground map, echoing the candidate, who privately told supporters at a virtual meeting of his finance committee on Thursday that he expected a major expansion of the playing field, according to two participants.

She indicated the campaign sees Arizona, Texas and Georgia as being in play. She is particularly "bullish," she said, on Arizona, a traditionally red state.