Pakistan president Asif Ali Zardari was among the first of the foreign leaders to greet prime minister Manmohan Singh for UPA's electoral win.

Zardari called up Singh on Saturday night to congratulate him for the poll victory, the PMO said.

The Pakistan president has been saying that he was waiting for the new government to assume office in India so that the bilateral dialogue could be resumed.

The dialogue has been suspended by India since the November 26 terror attacks in Mumbai and has maintained that it could resume only after Pakistan takes concrete action against those behind the strikes.

Bhutan King Jigme Khesar Namgyal Wangchuck and his father Jigme Singye Wangchuck wrote a letter to the prime minister congratulating him for the UPA's performance.