China said on Tuesday (local time) it had signed a security pact with the Solomon Islands, a move set to heighten the concerns of the United States and allies Australia and New Zealand about growing Chinese influence in a region traditionally under their sway.
The framework pact was recently signed by State Councilor and Foreign Minister Wang Yi and Solomon Islands Foreign Minister Jeremiah Manele, foreign ministry spokesman Wang Wenbin told reporters at a regular briefing in Beijing.
He did not give details of where, or precisely when, the signing took place.
Australian officials said it appeared the announcement had been made by Beijing ahead of the arrival of White House officials in Honiara.
Canberra is concerned that the pact, details of which have not been made public, could be a step towards a Chinese military presence less than 2,000 km (1,200 miles) from Australia.
Australia's foreign minister Marise Payne said Australia was "deeply disappointed" and continued to seek further clarity on the terms of the agreement, noting the signing had been announced by the Chinese government.
"We are concerned about the lack of transparency with which this agreement has been developed, noting its potential to undermine stability in our region," she said in a statement on Tuesday evening.
Australia's national broadcaster ABC reported an announcement would be made by Solomon Islands Prime Minister Manasseh Sogavare in the coming days.
Earlier on Tuesday the parliament of the Pacific islands nation was told that China would send officials to the Solomons next month to sign cooperation pacts.
Although the Chinese embassy and Solomon Islands officials had previously initialled the security pact that would allow Chinese police to protect infrastructure and social order, ministers had not yet signed it.
Last week, Zed Seselja, Australia's minister for international development and the Pacific, visited Honiara to ask Sogavare not to sign the security pact.
On Monday, the White House said a high-level US delegation including Indo-Pacific coordinator Kurt Campbell would also travel to Honiara this week to discuss concerns about China, as well as the reopening of a US embassy.
"Deliberate attempts to inflate tensions and mobilise rival camps are also doomed to fail," Wang, the Chinese spokesman, said on Tuesday, when asked about the US officials' scheduled visit.
Honiara's parliament was told by Douglas Ete, chairman of the public accounts committee and lawmaker for East Honiara, that Chinese foreign ministry officials would arrive next month.
"The PRC foreign affairs is heading to Honiara in the middle of May to sign multilateral agreements and cooperations with the Solomon Islands government," he said, referring to China.
Ete said the visit meant the two nations would increase cooperation on trade, education and fisheries, but added that he rejected the idea of the Solomons signing a security pact with China to set up a military base.
Sogavare told parliament the proposed security agreement would not include a Chinese military base.