External Affairs Minister Sushma Swaraj on Wednesday held a telephonic conversation with new US Secretary of State Rex Tillerson during which both leaders resolved to "further expand and deepen" India-US ties."The External Affairs Minister and Secretary Tillerson resolved to work together closely to further expand and deepen the multi-faceted strategic partnership between India and the US," the Ministry of External Affairs said in a statement here.It said the two leaders "emphasised that close and strong relations between India and the US were not only in mutual interest but also had regional and global significance". "In this context, they agreed to intensify cooperation in various sectors, including defence and security, energy, and economy," the statement said. Both also agreed to follow up the firm resolve expressed by Prime Minister Narendra Modi and US President Donald Trump "to cooperate closely in the global fight against terrorism".Tillerson assumed office as the Secretary of State under the new Trump administration on February 1.