(Reuters) -The Biden administration is working to get a group of U.S. doctors out of Gaza after Israel closed the Rafah border crossing, the White House said on Wednesday.

The State Department said earlier this week that the government was aware that American doctors were unable to leave Gaza, after the Intercept reported that upwards of 20 American doctors and medical workers were trapped in Gaza.

The Palestinian American Medical Association, a U.S.-based non-profit, said on Monday that its team of 19 healthcare professionals, including 10 Americans, had been denied exit from Gaza after a two-week mission providing medical services at the European Hospital in Khan Younis, a city near Rafah in southern Gaza.

Israel seized and closed the Rafah border crossing between Gaza and Egypt on May 7, disrupting a vital route for people and aid into and out of the devastated enclave.

"We're tracking this matter closely and working to get the impacted American citizens out of Gaza," White House Press Secretary Karine Jean-Pierre told reporters on Wednesday.

Jean-Pierre said the United States was engaging directly with Israel on the matter.

The Biden administration has been warning Israel against a major military ground operation in Rafah, but Jean-Pierre said efforts to get the doctors out are continuing regardless of what happens there.

"We need to get them out. We want to get them out and it has nothing to do with anything else," she said.

Israeli troops battled militants across Gaza on Wednesday, including in Rafah, which had been a refuge for civilians, in an upsurge of the more than seven-month-old war that has killed tens of thousands of Palestinians.

Gaza's healthcare system has essentially collapsed since Israel began its military offensive there after the Oct. 7 cross-border attacks by Palestinian Hamas militants on Israelis.

Humanitarian workers sounded the alarm last week that the closure of the Rafah and Kerem Shalom crossings into Gaza could force aid operations to grind to a halt.

The Israeli assault on Gaza has destroyed hospitals across Gaza, including Al Shifa Hospital, the Gaza Strip's largest before the war, and killed and injured health workers.

(Reporting by Nandita Bose; Writing by Brendan O'Boyle; Editing by Doina Chiacu and Eric Beech)