At a virtual meeting with G7 finance ministers and central bank governors earlier in the day, Yellen stressed the importance of providing further financial support to promote "a robust and lasting recovery," the US Treasury Department said in a statement.
"She emphasized that 'the time to go big is now' and that the G7 should be focused on what more we can do to provide support at this time," the statement said.
Yellen also said G7 countries should work with international financial institutions to address the challenges facing low-income countries that are struggling to respond to the pandemic, according to the Treasury Department.
Yellen's remarks came as US President Joe Biden's administration has stepped up efforts to push Congress to approve a USD 1.9-trillion COVID-19 relief package, which draws opposition from a growing number of congressional Republicans.
The G7 gathers Britain, Canada, France, Germany, Italy, Japan and the United States.
Britain is scheduled to host the first in-person G7 summit in almost two years in June this year, during which leaders will address shared challenges such as beating coronavirus and tackling climate change, according to the British Foreign, Commonwealth and Development Office.