The speaker said that it would have been a "snub" had Trump not taken the call with the president of Taiwan.
Trump's call with the president of Taiwan last week, which had reportedly been in the work for weeks, prompted a warning from China.
"It must be pointed out that there is only one China in the world," the Chinese foreign ministry said in a statement on Saturday. "We urge the relevant side in the U.S. to adhere to the 'one China' policy, abide by the pledges in the three joint China-U.S. communiques, and handle issues related to Taiwan carefully and properly to avoid causing unnecessary interference to the overall China-U.S. relationship."
Since Trump's calls, U.S. officials have reached out to China to stress America's commitment to the One-China policy, according to White House Press Secretary Josh Earnest.