4 September 2012 Last updated at 07:31 ET
Mrs Clinton said that the US does not take a position on competing territorial claims
US Secretary of State Hillary Clinton is heading for China, after talks in Indonesia which focused on tensions over the South China Sea.
In Indonesia she urged Asean to forge a united front on the issue and pushed for a code of conduct governing maritime territorial disputes.
China has called on the US not to involve itself in regional rows.
Mrs Clinton will be in Beijing for two days. Syria, Iran and North Korea are all expected to be on the agenda.
Mrs Clinton arrived in Jakarta, headquarters of the Association of South-East Asian Nations (Asean), late on Monday.
She arrives in Beijing late on Tuesday and will spend all of Wednesday meeting senior officials.
After China she is scheduled to visit East Timor and Brunei before heading to the Apec forum in Russia as part of her 11-day tour.
Territorial rowsChina has competing territorial claims with four Asean member-states in the South China Sea. The rows have led to increased tensions in the region.
Earlier this year, vessels from China and the Philippines faced off for several weeks over one area, the Scarborough Shoal.
Continue reading the main story[h=2]Analysis[/h]
Jonathan Marcus BBC Diplomatic Correspondent
The importance of the South China Sea island territories is clear - they represent footholds of sovereignty, sometimes of strategic importance - but also a ticket to the exploitation of natural resources such as minerals and fisheries.
Mrs Clinton may have chosen her words carefully but this is not really a moment for Sino-US harmony.
The political cycles in both countries - looming high-level leadership changes in Beijing and the presidential race in the US - mean that there is a good measure of nationalism on the one hand and some China-bashing on the other.
For Beijing, Washington's pivot to Asia and its new military strategy "AirSea Battle" suggest a policy of containing China.
And many in Washington fear that China's strident espousal of its territorial claims raise questions about its willingness to play the part of a responsible stake-holder in international affairs.
Mrs Clinton said on Tuesday that the US had a national interest in maintaining peace, stability and respect for international law in the region.
While the US "does not take a position on competing territorial claims", she said, "we believe the nations of the region should work collaboratively to resolve disputes without coercion, without intimidation and certainly without the use of force".
She also called on Asean nations to stand together on the issue.
At a regular meeting hosted by Cambodia in July, Asean failed for the first time in its 45-year history to issue a joint statement because of tensions over the disputes.
Vietnam and the Philippines have accused host Cambodia of yielding to Chinese pressure to keep the issue off the agenda.
'Strong opposition'Chinese media has been lukewarm ahead of her visit.
"Though US Secretary of State Hillary Clinton has said the Asia-Pacific is big enough to hold both China and the United States, Washington still need to take concrete actions to improve its ties with China," an article on state-run Xinhua news agency said.
"Moreover, Washington has been trying to work with a number of South East Asian nations to force China into a multi-national solution to territorial rows in the South China Sea, despite China's strong and perennial opposition."
China's Foreign Ministry also reinforced its stand on the disputes.
"We have noticed the United States has said many times that it will not hold a position on the South China Sea issue," said spokesman Hong Lei.
"We hope they can keep their promises and do more things that are conducive to regional peace and stability, not the opposite."
Mrs Clinton's last visit to China in 2 May was overshadowed by the diplomatic crisis over the blind Chinese activist Chen Guangcheng, who fled to the US embassy.
He was later allowed to go to New York to study.
US Secretary of State Hillary Clinton is heading for China, after talks in Indonesia which focused on tensions over the South China Sea.
In Indonesia she urged Asean to forge a united front on the issue and pushed for a code of conduct governing maritime territorial disputes.
China has called on the US not to involve itself in regional rows.
Mrs Clinton will be in Beijing for two days. Syria, Iran and North Korea are all expected to be on the agenda.
Mrs Clinton arrived in Jakarta, headquarters of the Association of South-East Asian Nations (Asean), late on Monday.
She arrives in Beijing late on Tuesday and will spend all of Wednesday meeting senior officials.
After China she is scheduled to visit East Timor and Brunei before heading to the Apec forum in Russia as part of her 11-day tour.
Territorial rowsChina has competing territorial claims with four Asean member-states in the South China Sea. The rows have led to increased tensions in the region.
Earlier this year, vessels from China and the Philippines faced off for several weeks over one area, the Scarborough Shoal.
Continue reading the main story[h=2]Analysis[/h]
The importance of the South China Sea island territories is clear - they represent footholds of sovereignty, sometimes of strategic importance - but also a ticket to the exploitation of natural resources such as minerals and fisheries.
Mrs Clinton may have chosen her words carefully but this is not really a moment for Sino-US harmony.
The political cycles in both countries - looming high-level leadership changes in Beijing and the presidential race in the US - mean that there is a good measure of nationalism on the one hand and some China-bashing on the other.
For Beijing, Washington's pivot to Asia and its new military strategy "AirSea Battle" suggest a policy of containing China.
And many in Washington fear that China's strident espousal of its territorial claims raise questions about its willingness to play the part of a responsible stake-holder in international affairs.
Mrs Clinton said on Tuesday that the US had a national interest in maintaining peace, stability and respect for international law in the region.
While the US "does not take a position on competing territorial claims", she said, "we believe the nations of the region should work collaboratively to resolve disputes without coercion, without intimidation and certainly without the use of force".
She also called on Asean nations to stand together on the issue.
At a regular meeting hosted by Cambodia in July, Asean failed for the first time in its 45-year history to issue a joint statement because of tensions over the disputes.
Vietnam and the Philippines have accused host Cambodia of yielding to Chinese pressure to keep the issue off the agenda.
'Strong opposition'Chinese media has been lukewarm ahead of her visit.
"Though US Secretary of State Hillary Clinton has said the Asia-Pacific is big enough to hold both China and the United States, Washington still need to take concrete actions to improve its ties with China," an article on state-run Xinhua news agency said.
"Moreover, Washington has been trying to work with a number of South East Asian nations to force China into a multi-national solution to territorial rows in the South China Sea, despite China's strong and perennial opposition."
China's Foreign Ministry also reinforced its stand on the disputes.
"We have noticed the United States has said many times that it will not hold a position on the South China Sea issue," said spokesman Hong Lei.
"We hope they can keep their promises and do more things that are conducive to regional peace and stability, not the opposite."
Mrs Clinton's last visit to China in 2 May was overshadowed by the diplomatic crisis over the blind Chinese activist Chen Guangcheng, who fled to the US embassy.
He was later allowed to go to New York to study.