How to change label fontsize on circlize chordDiagram in R

I have the following matrix:

> circ_mat 

      N chr Y   N LG1   N LG2    N PA N chr X N other
chr X    1546  128758  109464   71862 6926164  524087
PA      17415  140985  190831 7156005  145783  953412
chr 2   73977  157666 6588917  151092  137082 1027603
chr 1   17258 4552095 1414285  184986   70962  541434
chr Y   39822     921   12621    1688    4811   39199

And produce the chordDiagram as follows:

circos.clear()
circos.par(start.degree = 90, clock.wise = FALSE)

chordDiagram(circ_mat, annotationTrack = c("name", "grid"), 
             order = c("chr Y", "chr X", "chr 1", "chr 2", "PA", "N other", "N PA", "N LG2", "N LG1", "N chr X", "N chr Y"))

Producing the attached diagram. My question is: how can I make all the labels "chr X", "chr Y", etc bigger?

You can specify par settings before calling chordDiagram

par(cex = 3, mar = c(0, 0, 0, 0))