Sitharaman arrived on October 18 and will return home on October 21.
Defence Minister Nirmala Sitharaman on October 19 held a series of bilateral meetings with her counterparts from ASEAN nations and US Defence Secretary James Mattis on the sidelines of ASEAN Defence Ministers' Meet.
Defence Ministers from ASEAN countries and that of Australia, China, Japan, New Zealand, South Korea, Russia, and the US have gathered for the 12th ASEAN Defence Ministers' Meeting (ADMM) and the 5th ADMM-Plus, which is being hosted by Singapore.
The ADMM and ADMM-Plus serves as key Ministerial-level platforms in the regional security architecture, promoting strategic dialogue and practical cooperation between ASEAN and its partners.
"Smt @nsitharaman in a bilateral meeting with #SecDef James Mattis, United States Secretary of Defense on the sidelines of ASEAN Defence Ministers' Meet (Plus) in Singapore," the defence minister tweeted.
Sitharaman also met her Malaysian counterpart Mohamad bin Sabu, Australian Defence Minister Christopher Pyne, Philippines' Secretary of National Defense Delfin Lorenzana and Vietnam Defence Minister Ngo Xuan Lich during her fast-paced day-long meetings.
She will also hold a bilateral meeting with her Singapore counterpart Dr Ng Eng Hen.
According to sources, India and Singapore will extend their already comprehensive bilateral defence collaboration.
A new agreement is likely to be signed for the Army-to-Army collaboration as well as bilateral hosting of logistics and furthering supports for exchange visits by of naval vessels of the two countries, the sources said.
Both the countries conduct regular exercises involving the armed forces, navies and air forces.
India and Singapore will also be celebrating 25 years of SINBEX, an annual exercise with a two-week naval exercise programme in the Bay of Bengal in the coming weeks.Sitharaman arrived on October 18 and will return home on October 21.