Nauru, Kiribati and Fiji have received 50 ventilators to use for Covid-19 patients.
The ventilators were provided by the United States through its Agency for International Development.
The US Ambassador to the three countries, Joseph Cella, said while Kiribati and Nauru had no cases, Washington was scaling up their preparedness for the looming threat.
Fiji has seven cases of the virus in border quarantine
Cella said the life-saving equipment amounted to an additional $US11.4 million to US commitments to help Pacific countries prevent and control infectious diseases in health facilities.
The ambassador claimed his government continued to lead the global response to the pandemic having invested almost $US10 billion to "fight against this financially devastating and cruel plague".
"These ventilators, along with other US government development assistance in the region, represents our strong partnership and cooperation as Pacific neighbours, allies and partners to overcome this plague together," he said.
"The ventilators, manufactured in the United States, are used in intensive care units to support individuals whose lungs are not working adequately to get oxygen.
"USAID is also funding tailored packages of support that includes clinical training for the frontline health workers to safely use and maintain the ventilators."