WASHINGTON, Oct 27 (Reuters) - Senior Democratic and Republican U.S. senators introduced legislation on Wednesday seeking Washington's backing for Taiwan's admission to the Inter-American Development Bank as a non-borrowing member.

The bill is part of an ongoing effort in Congress and elsewhere in Washington to boost the international profile of Taiwan, as tensions escalate between the democratic-ruled island and China, which claims it as sovereign territory.

The measure would require the State Department to provide Congress with a strategy to secure diplomatic support for Taiwan's membership, a promotion from its current observer status.

The Senate has already passed legislation directing the State Department to develop a strategy to assist Taiwan in obtaining observer status at the World Health Assembly, the World Health Organization's decision-making body.

"We are committed to continue working to ensure the United States does everything in its power to champion Taiwan’s international engagement and demonstrate our unwavering commitment to the people of Taiwan," Senator Robert Menendez, Democratic chairman of the Senate Foreign Relations Committee, said in a statement.

China in recent weeks has staged repeated air missions over the Taiwan Strait, the waterway separating the island and the mainland.

Menendez introduced the bill with Democratic Senators Tim Kaine and Ed Markey and Republican Senators Jim Risch, Jim Inhofe and Marco Rubio. Risch is the top Republican on the foreign relations panel and Inhofe is the ranking Republican on the Senate Armed Services Committee.

The lawmakers said Taiwan has demonstrated that it can play an important role in the western hemisphere and contributes to the growth of economies in Latin America and the Caribbean.

Separately on Wednesday, President Joe Biden told Southeast Asian nations the United States would stand with them in defending freedom of the seas and democracy and called China's actions toward Taiwan "coercive" and a threat to peace and security. (Reporting by Patricia Zengerle; editing by Diane Craft)