German Chancellor Angela Merkel "cannot confirm" that she will attend a possible G7 summit of world leaders in Washington amid the coronavirus pandemic, a spokesperson at the Chancellery said Saturday.

US President Donald Trump has said the event could be hosted in Washington in late June, having previously announced in March that the summit would be held virtually.

"The Chancellor thanks President Trump for his invitation to the G7 summit in Washington at the end of June," Merkel's spokesperson said in a statement.

"As of today, given the overall pandemic situation, she cannot confirm her personal participation, that is, a trip to Washington," the spokesperson added.

Meanwhile, Germany's Health Minister, Jens Spahn, expressed his "disappointment" over the United States' withdrawal from the World Health Organization, saying that the decision taken by the Trump administration was a "setback" for international health policy.

Other world leaders have also been cagey with regards to Trump's proposed G7 summit.

Canadian Prime Minister Justin Trudeau said on Wednesday he could not yet commit to attending the proposed G7 meeting in person because of concerns over transmission of the virus and Canada's quarantine rules.

"There are significant health preoccupations that we have around holding it in person but there's no question that an in-person meeting in an ideal situation are much more effective than even virtual meetings," he said.

"However, there are many questions to answer before we can commit to showing up in-person and those discussions are happening in an ongoing and very constructive way."

French President Emmanuel Macron spoke with Trump on Thursday. The two leaders "agreed on the importance of convening the G7 in person in the near future," according to a White House readout of the call. But the White House did not say whether Macron had committed to attending in person.

Trump first mooted the idea of reviving the summit as an in-person event in a tweet on May 20, indicating that it would signal to the world that things are returning to normal after the coronavirus pandemic halted travel and froze the global economy.

"It looks like G7 may be on because we've done well, we're ahead of schedule in terms of our country and some of the other countries are doing very well," he said the following day on the South Lawn. "It looks like the G7 will be on, a full G7, and we'll be announcing something early next week."

Instead of Camp David, Trump suggested it would "probably" occur at the White House "but maybe a little combination at Camp David, but primarily at the White House."

US national security adviser Robert O'Brien told reporters at the time that he was on the phone with a "number of" his counterparts in Europe, and that "everybody wants to come to Washington."

"I can tell you countries around the world are trying to open up," O'Brien said. "All of the leaders are looking forward to coming to the White House if we can make it work."

The G7 is comprised of the US, Canada, France, the United Kingdom, Germany, Italy and Japan. Trump has mused about allowing Russia to rejoin the group but met fierce resistance from fellow leaders.