Georgetown University professor Victor Cha, who is reportedly under consideration for ambassador, has voiced concerns over South Korean support for increased contacts with Pyongyang.
President Rodrigo Duterte, military officials have promised to quickly defeat Maute Group at its base in Marawi city.
Monsoon rains have inundated parts of India and Pakistan this week.
Show of force also included military aircraft from Japan and Korea.
The trip comes amid fresh clashes between the army and Rohingya militants.
The standoff has further frayed ties between the two Asian countries.
Two Chinese officials with direct knowledge of the investigation said police are requesting a second Interpol arrest notice for Guo, 50.
Some analysts are offering criticism, saying contradictory statements are confusing US allies.
Analysts say measures ranging from naval and air blockade to bans on oil, textiles and labor could be used to squeeze Pyongyang even more.
Analysts see political purpose in latest provocation: a calculated signal to Washington, Seoul and Tokyo that Kim regime not interested in diplomacy, and will not stop its weapons tests.
Rohingya insurgent group, Arakan Rohingya Salvation Army, took responsibility for last week's attacks on more than 25 locations, saying they were in defense of Rohingya communities.
US president spoke with Japanese counterpart Tuesday about growing threat of Pyongyang's missile program.