Taiwan has sent senior diplomats to Gambia in a last-ditch effort to restore diplomatic relations after they were unilaterally broken off by the West African nation, officials said Sunday.

Foreign ministry spokeswoman Anna Kao said officials including Richard Shih, the island's ambassador to Gambia from 2008 through 2011, had arrived in Banjul.

She denied to provide details.

Local media said that since the Taiwanese officials had not been denied entry and were in contact with their Gambian foreign ministry counterparts, Taiwan's foreign ministry believes that the Gambian government "has not shut the door to negotiations".

Gambian President Yahya Jammeh announced Thursday that "in strategic national interest" his government had broken off diplomatic ties with Taiwan after 18 years, catching Taipei totally unprepared.

While Taipei expressed "shock and regret", the surprise decision has prompted speculation about Jammeh's motive.

China, which has growing investments and influence in Africa, has denied it put pressure on Gambia, although it did say that support for "the peaceful reunification of China is an irreversible trend".

Chinese foreign ministry spokesman Hong Lei said his country had learnt of Gambia's move from the foreign media.

"Before that, we haven't had contact with the Gambian side," he said.

Some scholars and politicians said Jammeh might use the drastic step, which reduces the number of countries recognising Taiwan to 22, to demand more aid from Taiwan as a condition for a change of heart.

"Should it demand a lot, the rest of the allies might follow in its footsteps, then how could the government deal with them?" said legislator Lin Yu-fang of the ruling Kuomintang party.

Taiwan and China were separated in 1949 after a civil war, but Beijing still claims the self-ruled island as part of its territory awaiting reunification, by force if necessary.

The two sides for years engaged in a bitter diplomatic tug-of-war, luring away each other's allies with generous financial packages.

But tensions eased markedly when Ma Ying-jeou of the China-friendly Kuomintang party was elected president in 2008. He was re-elected in January 2012.

Taiwan's opposition said the diplomatic setback marked the failure of Ma's diplomatic truce with China.