Sri Lanka Wednesday announced plans to replace its ageing jet fighters to better defend its maritime borders including rich fishing grounds, seven years after the island's separatist war ended.

Cabinet approved President Maithripala Sirisena's proposal to call for expressions of interest from global manufacturers to sell Sri Lanka the jets, government spokesman Rajitha Senaratne said.

"The idea is to buy eight multi-role fighter aircraft with associated weapons on a government-to-government basis," Senaratne, who is also a cabinet minister, told reporters.

Sri Lanka's fleet of Chinese-made F-7, Soviet-era MiG-27 and Israeli Kfir aircraft are about 30 years old and have become obsolete, according to experts.

Sri Lanka used both the MiG-27 and Kfir jets to bomb rebel targets in the north at the height of the Tamil separatist war which ended in May 2009.

The country lost large numbers of aircraft during the decades-long fighting.

The main role of the new fleet would be to defend the island's exclusive economic zone which stretches some 200 nautical miles (370 kilometres) offshore, senior sources in the government said.

Both neighbouring India and its rival Pakistan are keen to sell combat aircraft to the island, they said.