Intel CEO Lip-Bu Tan says he’s “always operated within the highest legal and ethical standards” after coming under pressure following President Donald Trump’s call for him to resign.

Republican Sen. Tom Cotton wrote a letter to Intel’s board with questions about CEO Lip-Bu Tan’s ties to Chinese firms.

Intel CEO Lip-Bu Tan has responded to President Donald Trump’s call for his resignation over alleged conflicts of interest. In a memo sent to staff on Thursday, Tan said those concerns are based on “misinformation.”