Security at US Conventions was Concern Even Before Nice Attack

The first convention starts in Cleveland on Monday.

Authorities have not announced any updates to convention security plans since the Nice attack, but were already preparing for the possibility of violence at demonstrations or other events surrounding the national political gatherings.

Johnson himself went to Cleveland today to review preparedness and will do the same in Philadelphia ahead of the Democratic convention.

The Cleveland police department did not immediately return ABC News' calls about any possible changes to their security plan in light of the attack on Nice.

One thing in Ohio that officials said may present particular challenges is the state's open-carry gun laws. While guns will not be allowed inside the convention center, where the Secret Service will oversee security, the state's laws mandate that people directly outside the building could carry legal weapons.

ABC News' Mike Levine contributed to this report.