Taiwan denied reports Monday that Singapore is suspending its long-standing military cooperation with the island after news of a rare visit by Taiwan's defence minister to the city state was made public.

The Taipei-based United Daily News reported Monday that Singapore, which recognises Beijing rather than Taipei, was unhappy at the media exposure of Kao Hua-chu's visit to Singapore in mid-February.

It said a Singaporean colonel acting on his government's behalf had delivered a protest letter to Kao last week, claiming publicity surrounding the visit violated the tacit understanding the trip would be kept secret.

"The report is absolutely not true," Taiwan's defence ministry said in a statement, adding that Taiwan treasures its friendship with Singapore and would like to increase exchanges between the two sides.

However, the ministry admitted "there will be an adjustment of some activities due to the needs of the two sides", suggesting ties between Taipei and Singapore may have been dented.

Defence ministry spokesman David Lo declined to elaborate, but a source close to the ministry confirmed that the scheduled visit to Singapore late this month by a Taiwanese army general has been scrapped.

Taiwan does not have formal diplomatic ties with Singapore but has provided training venues for Singapore's artillery, armoured vehicles and infantry units under a programme of military cooperation known as Operation Hsing Kuang or Starlight.

Taiwan's close ties with Singapore stretch back to the 1960s when it sent air force and naval officers to the city state during its early years of independence.

However, Singapore, like most countries, officially recognises China and is said to be keen on keeping its military exchanges with Taiwan as low-profile as possible.

In the past, top Singaporean officials' visits to Taiwan triggered strong protests from China.

China still claims Taiwan as part of its territory awaiting unification, by force if necessary, although ties have improved markedly since Taiwan's Beijing-friendly government came to power in 2008.