US intelligence chief Tulsi Gabbard on Wednesday said Pakistan, along with Russia, China and North Korea, currently posed the most significant nuclear threat to the country.Gabbard, Director of National Intelligence, was briefing the US Senate on Iran. Speaking on the evolving threat landscape, she said the US “obliterated” Iran’s nuclear enrichment programme in June last year.She said the US had since seen no effort to rebuild Iran’s enrichment capabilities.Gabbard said the US intelligence assessed a sharp rise in the number of missiles capable of striking the US.According to estimates, the figure is expected to grow to over 16,000 by 2035, a significant increase from the current assessed number of around 3,000, Reuters reported.During the briefing, Gabbard also named Iran, China, Russia and North Korea, saying they were actively developing new missile delivery systems, including both nuclear and conventional warheads, which put the US within range.“The intelligence community assesses that Russia, China, North Korea, Iran and Pakistan have been researching and developing an array of novel, advanced or traditional missile delivery systems, with nuclear and conventional payloads, that put our homeland within range,” Gabbard said.During the briefing, the US intelligence chief also said North Korea was strengthening its partnership with Russia and China.