US President Barack Obama will meet leaders from the 10-member Association of Southeast Asian Nations (ASEAN) in Southern California on Monday.

The two-day summit will be held at Sunnylands in Rancho Mirage, the same place where Obama held his famous "shirt-sleeves summit" with Chinese President Xi Jinping three years ago.

The agenda for the ASEAN meeting, the first to be held on U.S. soil, covers a broad spectrum of issues, including security, trade and climate change.

Analysts said the meeting comes as the U.S. steps up its efforts to support its Southeast Asian allies in order to counter China's growing influence in the region.

South China Sea tensions

Some ASEAN leaders are concerned about China’s growing boldness in the South China Sea.

The Philippines and Vietnam are two of the countries involved in territorial disputes with China - and leaders from both countries want guarantees from the US over security.

Other ASEAN member countries, however, do not want to anger Chinese leaders with bold US action.

This lack of consensus over Chinese policy currently divides ASEAN's member nations and could prove to be a stumbling block for any major developments in the summit.

One popular idea suggested by analysts is that the U.S. could do more to support ASEAN efforts by negotiating a Code of Conduct with China in order to help ease regional tensions.

Economic powerhouse

The U.S.-ASEAN axis, a key part of Obama's much-heralded "pivot to Asia" strategy, is also seen as one of the most important economic milestones for the White House.

The 10-nation axis is crucial for the growth of many American companies - US firms are the largest foreign direct investors with a total investment currently totalling $226bn.

The ASEAN region is already America's fourth largest export market and contributes over half a million jobs in the U.S..

The 10-nation bloc also represents the world's seventh largest economy, with a population of around 625 million people.

Human rights concerns

Yet, some critics have said that as the U.S. bids to counter China's influences in South Asia, it is also ignoring a worsening situation for human rights, transparency and democracy in parts of the region.

Among the attendees at the summit will be Najib Razak, the Malaysian prime minister, whose presence is expected to be dominated by questions over the almost $700m in his bank account.

Concerns have also been raised over the future of his political rival, Anwar Ibrahim, who has been imprisoned for more than a year on a widely questioned sodomy conviction.

Razak will be joined by Hun Sen, the Cambodian prime minister, who has ruled the country since the 1980s - but has long faced accusations of authoritarianism.

In Vietnam, the press is under state control and critical bloggers have been jailed for "abusing democratic freedoms".

Concerns also remain over the legitimacy of Thailand’s military ruler Prayuth Chan-ocha, who has been quick to silence internal criticism and has failed to hold elections since his junta replaced an elected government in May 2014.

"The risk is that the Sunnylands summit will empower and embolden ASEAN leaders who have been responsible for jailing journalists, cracking down on peaceful protesters, and dismantling democratic institutions after coups," said John Sifton, Asia advocacy director for Human Rights Watch.

More than 100 Southeast Asian politicians have also urged Obama to address human rights issues during his meetings with Asian leaders, according to an open letter posted online on Thursday.

The letter was signed predominantly by politicians from Malaysia, Cambodia and Indonesia, urging Obama to "press [leaders] on unfulfilled human rights commitments and to directly raise specific concerns with them".

The politicians said that many of the participating countries have taken "dramatic steps backward" in democratic principles in recent years.

Source: Al Jazeera