Hillary Clinton, the presumptive Democratic presidential nominee, made a surprise appearance at the NYC Pride March on Sunday.

Surrounded by security, Clinton marched alongside Mayor Bill de Blasio and Gov. Andrew M. Cuomo, waving to the crowd. She did not make any official speech at the march.

The former secretary of state posted a number of tweets Sunday, expressing support for the LGBT community.

"One year ago, love triumphed in our highest court. Yet LGBT Americans still face too many barriers. Let's keep marching until they don't. -H," one of her tweets read.

This year's pride parade marks a year after the Supreme Court made same-sex marriage legal in all 50 states. It also comes just two weeks after 49 people were killed and more than 50 were injured in a mass shooting at a gay nightclub in Orlando, Florida.

"The Orlando terrorist may be dead, but the virus that poisoned his mind remains very strong, and we must attack it," Clinton said in a speech following the massacre.

The Human Rights Campaign, the largest LGBT civil rights group in the country, endorsed Clinton for president at the beginning of the year.