The South Pacific island nation of Nauru says it is severing relations with Taiwan and reestablishing diplomatic ties with China.

Nauru's government said in a statement on Monday that the move is in the best interest of the country and its people.

It said Nauru will no longer recognize Taiwan as a separate country, but rather as an inalienable part of China's territory. It also said the country will "sever diplomatic relations with Taiwan as of this day and no longer develop any official relations or official exchanges with Taiwan."

The island nation has a population of about 12,000 and a land area of 21 square kilometers.

It established diplomatic ties with China in 2002. But it established diplomatic relations with Taiwan and broke off the ties with China in 2005.

Nauru's decision is prompting observers to speculate on what was behind the move, as it had recently been critical of Beijing.

China's Foreign Ministry on Monday welcomed Nauru's decision. Ministry spokesperson Mao Ning told reporters that China stands ready to work with Nauru to open a new chapter of bilateral relations on the basis of the one-China principle.

Regarding the timing of Nauru's announcement, which came immediately after Taiwan's presidential election, Mao said it was Nauru's voluntary choice as a sovereign state.

Taiwan had diplomatic ties with 22 countries when President Tsai Ing-wen of the Democratic Progressive Party took office in May 2016.

But China has been pressuring countries to cut ties with Taiwan, as Tsai's administration rejects Beijing's claim that Taiwan is a part of its territory.

A total of 10 countries have severed ties with Taiwan -- five countries in Central America and the Caribbean, three countries in Oceania, including Nauru, and two countries in Africa. This brings to 12 the number of countries that have diplomatic relations with Taiwan.

Taiwan's presidential office said on Monday that Beijing's diplomatic repression immediately after its presidential election is a retaliation against democratic values and a blatant challenge against a stable international order.