Republican and Democratic US senators have introduced legislation to discourage Taiwan's few remaining allies from switching their allegiance to China.
El Salvador became the third country this year to move towards Beijing.
The legislation would authorise the State Department to downgrade US relations with any government that shifts away from Taiwan, and to suspend or alter US assistance.
It also requires a US strategy to engage with governments to support Taiwan's diplomatic recognition or strengthen unofficial ties with Taiwan.
Washington does not recognise Taipei diplomatically but considers it a staunch ally in the Pacific Rim.
The Pacific island region is important for Taiwan with Palau, Marshall Islands, Solomon Islands, Nauru, Tuvalu and Kiribati all recognising Taipei over Beijing.