Section 906 Certifications

I, Jonathan S. Horwitz, the Principal Executive Officer of the Funds listed on Attachment A, certify that, to my knowledge:

1. The form N-CSR of the Funds listed on Attachment A for the period ended December 31, 2021 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Form N-CSR of the Funds listed on Attachment A for the period ended December 31, 2021 fairly presents, in all material respects, the financial condition and results of operations of the Funds listed on Attachment A.

Date: February 25, 2022

/s/ Jonathan S. Horwitz

______________________

Jonathan S. Horwitz

Principal Executive Officer

Section 906 Certifications

I, Janet C. Smith, the Principal Financial Officer of the Funds listed on Attachment A, certify that, to my knowledge:

1. The form N-CSR of the Funds listed on Attachment A for the period ended December 31, 2021 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Form N-CSR of the Funds listed on Attachment A for the period ended December 31, 2021 fairly presents, in all material respects, the financial condition and results of operations of the Funds listed on Attachment A.

Date: February 25, 2022

/s/ Janet C. Smith

______________________

Janet C. Smith

Principal Financial Officer

Attachment A

Period (s) ended December 31, 2021

               Putnam International Equity Fund

               Putnam International Value Fund

               Putnam Small Cap Growth Fund

               Putnam Sustainable Leaders Fund

               Putnam VT Diversified Income Fund

               Putnam VT Emerging Markets Equity Fund

               Putnam VT Focused International Equity Fund

               Putnam VT George Putnam Balanced Fund

               Putnam VT Global Asset Allocation Fund

               Putnam VT Global Health Care Fund

               Putnam VT Government Money Market Fund

               Putnam VT Growth Opportunities Fund

               Putnam VT High Yield Fund

               Putnam VT Income Fund

               Putnam VT International Equity Fund

               Putnam VT International Value Fund

               Putnam VT Large Cap Value Fund

               Putnam VT Mortgage Securities Fund

               Putnam VT Multi-Asset Absolute Return Fund

               Putnam VT Multi-Cap Core Fund

               Putnam VT Research Fund

               Putnam VT Small Cap Growth Fund

               Putnam VT Small Cap Value Fund

               Putnam VT Sustainable Future Fund

               Putnam VT Sustainable Leaders Fund