WASHINGTON, Sept 13 (Reuters) - Taiwan's de facto ambassador in Washington, Hsiao Bi-khim, on Tuesday hosted dozens of international lawmakers who back sanctions on China for aggression toward the island, a show of support for Taipei amid military pressure from Beijing.

The unannounced gathering of about 60 parliamentarians from Europe, Asia and Africa at Taiwan's sweeping hilltop diplomatic mansion in Washington - called Twin Oaks - is the latest move in Taipei's efforts to persuade fellow democracies to stand against China since Russia's invasion of Ukraine heightened concerns that Beijing could attempt to take the island by force.

The group, consisting of members of the Inter-Parliamentary Alliance on China (IPAC) gathering in Washington this week, is expected to sign a pledge to push their governments to adopt "greater deterrence against military or other coercive" actions by the People's Republic of China (PRC) against Taiwan, according to a draft seen by Reuters.

"We will campaign to ensure our governments signal to the PRC that military aggression towards Taiwan will cost Beijing dearly. Economic and political measures, including meaningful sanctions, should be considered to deter military escalation, and to ensure trade and other exchanges with Taiwan can continue unimpeded," the draft said.

It added that their countries' ties to Taiwan were not Beijing's to determine, and that they would push to increase mutual visits by lawmakers.

Chinese President Xi Jinping has vowed to bring democratically governed Taiwan under Beijing's control and has not ruled out the use of force. He is set to secure a third, five-year leadership term at a Communist Party congress next month. Taiwan's government strongly rejects China's sovereignty claims.

Sources familiar with the issue have told Reuters that Washington is considering sanctions against China to deter it from invading Taiwan, with the European Union coming under diplomatic pressure from Taipei to do the same.

Hsiao, speaking to the lawmakers - who according to a guest list seen by Reuters hailed from countries including the U.K., Australia, Canada, India, Japan, Lithuania, Ukraine, New Zealand and the Netherlands - told the gathering: "It is important to demonstrate to the bully that we have friends too.

"We are not seeking to provoke the bully, but neither will we bow to their pressure."

She welcomed two Ukrainian representatives at the event.

"We certainly hope that as the international community stands with Ukraine, that the international community will also stand with Taiwan... that together we can deter the further aggression coming from China."

The IPAC pledge, expected to be signed on Wednesday, also calls for countries to secure supply chains from forced labor in China's Xinjiang region, and to pursue sanctions on Chinese officials for abuses in Hong Kong, and on Chinese companies that support Russia's military industry.

China's embassy in Washington did not immediately respond to a request for comment.